LinuxLists.cc - [RFC][PATCH 0/5] Introduce drm scaling filter property

2020-02-25 07:18:02

Subject: [RFC][PATCH 0/5] Introduce drm scaling filter property

2020-02-25 07:18:13

Subject: [RFC][PATCH 5/5] drm/i915/display: Add Nearest-neighbor based integer scaling support

Integer scaling (IS) is a nearest-neighbor upscaling technique that
simply scales up the existing pixels by an integer
(i.e., whole number) multiplier.Nearest-neighbor (NN) interpolation
works by filling in the missing color values in the upscaled image
with that of the coordinate-mapped nearest source pixel value.

Both IS and NN preserve the clarity of the original image. Integer
scaling is particularly useful for pixel art games that rely on
sharp, blocky images to deliver their distinctive look.

Program the scaler filter coefficients to enable the NN filter if
scaling filter property is set to DRM_SCALING_FILTER_NEAREST_NEIGHBOR
and enable integer scaling.

Bspec: 49247

Signed-off-by: Pankaj Bharadiya <[email protected]>
Signed-off-by: Ankit Nautiyal <[email protected]>
---
drivers/gpu/drm/i915/display/intel_display.c | 83 +++++++++++++++++++-
drivers/gpu/drm/i915/display/intel_display.h | 2 +
drivers/gpu/drm/i915/display/intel_sprite.c | 20 +++--
3 files changed, 97 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index b5903ef3c5a0..6d5f59203258 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -6237,6 +6237,73 @@ void skl_scaler_disable(const struct intel_crtc_state *old_crtc_state)
skl_detach_scaler(crtc, i);
}

+/**
+ * Theory behind setting nearest-neighbor integer scaling:
+ *
+ * 17 phase of 7 taps requires 119 coefficients in 60 dwords per set.
+ * The letter represents the filter tap (D is the center tap) and the number
+ * represents the coefficient set for a phase (0-16).
+ *
+ * +------------+------------------------+------------------------+
+ * |Index value | Data value coeffient 1 | Data value coeffient 2 |
+ * +------------+------------------------+------------------------+
+ * | 00h | B0 | A0 |
+ * +------------+------------------------+------------------------+
+ * | 01h | D0 | C0 |
+ * +------------+------------------------+------------------------+
+ * | 02h | F0 | E0 |
+ * +------------+------------------------+------------------------+
+ * | 03h | A1 | G0 |
+ * +------------+------------------------+------------------------+
+ * | 04h | C1 | B1 |
+ * +------------+------------------------+------------------------+
+ * | ... | ... | ... |
+ * +------------+------------------------+------------------------+
+ * | 38h | B16 | A16 |
+ * +------------+------------------------+------------------------+
+ * | 39h | D16 | C16 |
+ * +------------+------------------------+------------------------+
+ * | 3Ah | F16 | C16 |
+ * +------------+------------------------+------------------------+
+ * | 3Bh | Reserved | G16 |
+ * +------------+------------------------+------------------------+
+ *
+ * To enable nearest-neighbor scaling: program scaler coefficents with
+ * the center tap (Dxx) values set to 1 and all other values set to 0 as per
+ * SCALER_COEFFICIENT_FORMAT
+ *
+ */
+void skl_setup_nearest_neighbor_filter(struct drm_i915_private *dev_priv,
+ enum pipe pipe, int scaler_id)
+{
+
+ int coeff = 0;
+ int phase = 0;
+ int tap;
+ int val = 0;
+
+ /*enable the index auto increment.*/
+ intel_de_write_fw(dev_priv, SKL_PS_COEF_INDEX_SET0(pipe, scaler_id),
+ _PS_COEE_INDEX_AUTO_INC);
+
+ for (phase = 0; phase < 17; phase++) {
+ for (tap = 0; tap < 7; tap++) {
+ coeff++;
+ if (tap == 3)
+ val = (phase % 2) ? (0x800) : (0x800 << 16);
+
+ if (coeff % 2 == 0) {
+ intel_de_write_fw(dev_priv, SKL_PS_COEF_DATA_SET0(pipe, scaler_id), val);
+ val = 0;
+ }
+
+ }
+
+ }
+
+ intel_de_write_fw(dev_priv, SKL_PS_COEF_DATA_SET0(pipe, scaler_id), 0);
+}
+
static void skl_pfit_enable(const struct intel_crtc_state *crtc_state)
{
struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
@@ -6260,9 +6327,23 @@ static void skl_pfit_enable(const struct intel_crtc_state *crtc_state)
pfit_w = (crtc_state->pch_pfit.size >> 16) & 0xFFFF;
pfit_h = crtc_state->pch_pfit.size & 0xFFFF;

+ id = scaler_state->scaler_id;
+
if (state->scaling_filter ==
DRM_SCALING_FILTER_NEAREST_NEIGHBOR) {
scaling_filter = PS_FILTER_PROGRAMMED;
+ skl_setup_nearest_neighbor_filter(dev_priv, pipe, id);
+
+ /* Make the scaling window size to integer multiple of
+ * source.
+ *
+ * TODO: Should userspace take desision to round
+ * scaling window to integer multiple?
+ */
+ pfit_w = rounddown(pfit_w,
+ (crtc_state->pipe_src_w << 16));
+ pfit_h = rounddown(pfit_h,
+ (crtc_state->pipe_src_h << 16));
}

hscale = (crtc_state->pipe_src_w << 16) / pfit_w;
@@ -6271,8 +6352,6 @@ static void skl_pfit_enable(const struct intel_crtc_state *crtc_state)
uv_rgb_hphase = skl_scaler_calc_phase(1, hscale, false);
uv_rgb_vphase = skl_scaler_calc_phase(1, vscale, false);

- id = scaler_state->scaler_id;
-
spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);

intel_de_write_fw(dev_priv, SKL_PS_CTRL(pipe, id),
diff --git a/drivers/gpu/drm/i915/display/intel_display.h b/drivers/gpu/drm/i915/display/intel_display.h
index f92efbbec838..49f58d3c98fe 100644
--- a/drivers/gpu/drm/i915/display/intel_display.h
+++ b/drivers/gpu/drm/i915/display/intel_display.h
@@ -586,6 +586,8 @@ void intel_crtc_arm_fifo_underrun(struct intel_crtc *crtc,
u16 skl_scaler_calc_phase(int sub, int scale, bool chroma_center);
int skl_update_scaler_crtc(struct intel_crtc_state *crtc_state);
void skl_scaler_disable(const struct intel_crtc_state *old_crtc_state);
+void skl_setup_nearest_neighbor_filter(struct drm_i915_private *dev_priv,
+ enum pipe pipe, int scaler_id);
void ilk_pfit_disable(const struct intel_crtc_state *old_crtc_state);
u32 glk_plane_color_ctl(const struct intel_crtc_state *crtc_state,
const struct intel_plane_state *plane_state);
diff --git a/drivers/gpu/drm/i915/display/intel_sprite.c b/drivers/gpu/drm/i915/display/intel_sprite.c
index fd7b31a21723..5bef5c031374 100644
--- a/drivers/gpu/drm/i915/display/intel_sprite.c
+++ b/drivers/gpu/drm/i915/display/intel_sprite.c
@@ -415,18 +415,26 @@ skl_program_scaler(struct intel_plane *plane,
u16 y_vphase, uv_rgb_vphase;
int hscale, vscale;
const struct drm_plane_state *state = &plane_state->uapi;
+ u32 src_w = drm_rect_width(&plane_state->uapi.src) >> 16;
+ u32 src_h = drm_rect_height(&plane_state->uapi.src) >> 16;
u32 scaling_filter = PS_FILTER_MEDIUM;
+ struct drm_rect dst;

if (state->scaling_filter == DRM_SCALING_FILTER_NEAREST_NEIGHBOR) {
scaling_filter = PS_FILTER_PROGRAMMED;
+ skl_setup_nearest_neighbor_filter(dev_priv, pipe, scaler_id);
+
+ /* Make the scaling window size to integer multiple of source
+ * TODO: Should userspace take desision to round scaling window
+ * to integer multiple?
+ */
+ crtc_w = rounddown(crtc_w, src_w);
+ crtc_h = rounddown(crtc_h, src_h);
}

- hscale = drm_rect_calc_hscale(&plane_state->uapi.src,
- &plane_state->uapi.dst,
- 0, INT_MAX);
- vscale = drm_rect_calc_vscale(&plane_state->uapi.src,
- &plane_state->uapi.dst,
- 0, INT_MAX);
+ drm_rect_init(&dst, crtc_x, crtc_y, crtc_w, crtc_h);
+ hscale = drm_rect_calc_hscale(&plane_state->uapi.src, &dst, 0, INT_MAX);
+ vscale = drm_rect_calc_vscale(&plane_state->uapi.src, &dst, 0, INT_MAX);

/* TODO: handle sub-pixel coordinates */
if (intel_format_info_is_yuv_semiplanar(fb->format, fb->modifier) &&
--
2.23.0

2020-02-25 07:18:21

by Laxminarayan Bharadiya, Pankaj

[permalink] [raw]

Subject: [RFC][PATCH 2/5] drm/drm-kms.rst: Add Scaling filter property documentation

Add documentation for newly introduced KMS scaling filter property.

Signed-off-by: Pankaj Bharadiya <[email protected]>
---
Documentation/gpu/drm-kms.rst | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/Documentation/gpu/drm-kms.rst b/Documentation/gpu/drm-kms.rst
index 906771e03103..7b71a1e3edda 100644
--- a/Documentation/gpu/drm-kms.rst
+++ b/Documentation/gpu/drm-kms.rst
@@ -509,6 +509,12 @@ Variable Refresh Properties
.. kernel-doc:: drivers/gpu/drm/drm_connector.c
:doc: Variable refresh properties

+Scaling Filter Property
+-----------------------
+
+.. kernel-doc:: drivers/gpu/drm/drm_plane.c
+ :doc: Scaling filter property
+
Existing KMS Properties
-----------------------

--
2.23.0

2020-02-25 07:18:42

by Laxminarayan Bharadiya, Pankaj

[permalink] [raw]

Subject: [RFC][PATCH 3/5] drm/i915: Enable scaling filter for plane and pipe

Attach scaling filter property for crtc and plane and program the
scaler control register for the selected filter type.

This is preparatory patch to enable Nearest-neighbor integer scaling.

Signed-off-by: Pankaj Bharadiya <[email protected]>
Signed-off-by: Ankit Nautiyal <[email protected]>
---
drivers/gpu/drm/i915/display/intel_display.c | 17 +++++++++++++++--
drivers/gpu/drm/i915/display/intel_sprite.c | 12 +++++++++++-
drivers/gpu/drm/i915/i915_reg.h | 1 +
3 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 3031e64ee518..b5903ef3c5a0 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -6242,6 +6242,8 @@ static void skl_pfit_enable(const struct intel_crtc_state *crtc_state)
struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
enum pipe pipe = crtc->pipe;
+ const struct drm_crtc_state *state = &crtc_state->uapi;
+ u32 scaling_filter = PS_FILTER_MEDIUM;
const struct intel_crtc_scaler_state *scaler_state =
&crtc_state->scaler_state;

@@ -6258,6 +6260,11 @@ static void skl_pfit_enable(const struct intel_crtc_state *crtc_state)
pfit_w = (crtc_state->pch_pfit.size >> 16) & 0xFFFF;
pfit_h = crtc_state->pch_pfit.size & 0xFFFF;

+ if (state->scaling_filter ==
+ DRM_SCALING_FILTER_NEAREST_NEIGHBOR) {
+ scaling_filter = PS_FILTER_PROGRAMMED;
+ }
+
hscale = (crtc_state->pipe_src_w << 16) / pfit_w;
vscale = (crtc_state->pipe_src_h << 16) / pfit_h;

@@ -6268,8 +6275,10 @@ static void skl_pfit_enable(const struct intel_crtc_state *crtc_state)

spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);

- intel_de_write_fw(dev_priv, SKL_PS_CTRL(pipe, id), PS_SCALER_EN |
- PS_FILTER_MEDIUM | scaler_state->scalers[id].mode);
+ intel_de_write_fw(dev_priv, SKL_PS_CTRL(pipe, id),
+ PS_SCALER_EN |
+ scaling_filter |
+ scaler_state->scalers[id].mode);
intel_de_write_fw(dev_priv, SKL_PS_VPHASE(pipe, id),
PS_Y_PHASE(0) | PS_UV_RGB_PHASE(uv_rgb_vphase));
intel_de_write_fw(dev_priv, SKL_PS_HPHASE(pipe, id),
@@ -16695,6 +16704,10 @@ static int intel_crtc_init(struct drm_i915_private *dev_priv, enum pipe pipe)
dev_priv->plane_to_crtc_mapping[i9xx_plane] = crtc;
}

+
+ if (INTEL_GEN(dev_priv) >= 11)
+ drm_crtc_enable_scaling_filter(&crtc->base);
+
intel_color_init(crtc);

drm_WARN_ON(&dev_priv->drm, drm_crtc_index(&crtc->base) != crtc->pipe);
diff --git a/drivers/gpu/drm/i915/display/intel_sprite.c b/drivers/gpu/drm/i915/display/intel_sprite.c
index 7abeefe8dce5..fd7b31a21723 100644
--- a/drivers/gpu/drm/i915/display/intel_sprite.c
+++ b/drivers/gpu/drm/i915/display/intel_sprite.c
@@ -414,6 +414,12 @@ skl_program_scaler(struct intel_plane *plane,
u16 y_hphase, uv_rgb_hphase;
u16 y_vphase, uv_rgb_vphase;
int hscale, vscale;
+ const struct drm_plane_state *state = &plane_state->uapi;
+ u32 scaling_filter = PS_FILTER_MEDIUM;
+
+ if (state->scaling_filter == DRM_SCALING_FILTER_NEAREST_NEIGHBOR) {
+ scaling_filter = PS_FILTER_PROGRAMMED;
+ }

hscale = drm_rect_calc_hscale(&plane_state->uapi.src,
&plane_state->uapi.dst,
@@ -441,7 +447,8 @@ skl_program_scaler(struct intel_plane *plane,
}

intel_de_write_fw(dev_priv, SKL_PS_CTRL(pipe, scaler_id),
- PS_SCALER_EN | PS_PLANE_SEL(plane->id) | scaler->mode);
+ scaling_filter | PS_SCALER_EN |
+ PS_PLANE_SEL(plane->id) | scaler->mode);
intel_de_write_fw(dev_priv, SKL_PS_VPHASE(pipe, scaler_id),
PS_Y_PHASE(y_vphase) | PS_UV_RGB_PHASE(uv_rgb_vphase));
intel_de_write_fw(dev_priv, SKL_PS_HPHASE(pipe, scaler_id),
@@ -3104,6 +3111,9 @@ skl_universal_plane_create(struct drm_i915_private *dev_priv,

drm_plane_create_zpos_immutable_property(&plane->base, plane_id);

+ if (INTEL_GEN(dev_priv) >= 11)
+ drm_plane_enable_scaling_filter(&plane->base);
+
drm_plane_helper_add(&plane->base, &intel_plane_helper_funcs);

return plane;
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index f45b5e86ec63..34923b1c284c 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -7212,6 +7212,7 @@ enum {
#define PS_PLANE_SEL(plane) (((plane) + 1) << 25)
#define PS_FILTER_MASK (3 << 23)
#define PS_FILTER_MEDIUM (0 << 23)
+#define PS_FILTER_PROGRAMMED (1 << 23)
#define PS_FILTER_EDGE_ENHANCE (2 << 23)
#define PS_FILTER_BILINEAR (3 << 23)
#define PS_VERT3TAP (1 << 21)
--
2.23.0

2020-02-25 07:18:47

by Laxminarayan Bharadiya, Pankaj

[permalink] [raw]

Subject: [RFC][PATCH 4/5] drm/i915: Introduce scaling filter related registers and bit fields.

Introduce scaler registers and bit fields needed to configure the
scaling filter in prgrammed mode and configure scaling filter
coefficients.

Signed-off-by: Pankaj Bharadiya <[email protected]>
Signed-off-by: Ankit Nautiyal <[email protected]>
---
drivers/gpu/drm/i915/i915_reg.h | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 34923b1c284c..bba4ad3be611 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -7289,6 +7289,18 @@ enum {
#define _PS_ECC_STAT_2B 0x68AD0
#define _PS_ECC_STAT_1C 0x691D0

+#define _PS_COEF_SET0_INDEX_1A 0x68198
+#define _PS_COEF_SET0_INDEX_2A 0x68298
+#define _PS_COEF_SET0_INDEX_1B 0x68998
+#define _PS_COEF_SET0_INDEX_2B 0x68A98
+
+#define _PS_COEF_SET0_DATA_1A 0x6819C
+#define _PS_COEF_SET0_DATA_2A 0x6829C
+#define _PS_COEF_SET0_DATA_1B 0x6899C
+#define _PS_COEF_SET0_DATA_2B 0x68A9C
+
+#define _PS_COEE_INDEX_AUTO_INC (1 << 10)
+
#define _ID(id, a, b) _PICK_EVEN(id, a, b)
#define SKL_PS_CTRL(pipe, id) _MMIO_PIPE(pipe, \
_ID(id, _PS_1A_CTRL, _PS_2A_CTRL), \
@@ -7318,6 +7330,14 @@ enum {
_ID(id, _PS_ECC_STAT_1A, _PS_ECC_STAT_2A), \
_ID(id, _PS_ECC_STAT_1B, _PS_ECC_STAT_2B))

+#define SKL_PS_COEF_INDEX_SET0(pipe, id) _MMIO_PIPE(pipe, \
+ _ID(id, _PS_COEF_SET0_INDEX_1A, _PS_COEF_SET0_INDEX_2A), \
+ _ID(id, _PS_COEF_SET0_INDEX_1B, _PS_COEF_SET0_INDEX_2B))
+
+#define SKL_PS_COEF_DATA_SET0(pipe, id) _MMIO_PIPE(pipe, \
+ _ID(id, _PS_COEF_SET0_DATA_1A, _PS_COEF_SET0_DATA_2A), \
+ _ID(id, _PS_COEF_SET0_DATA_1B, _PS_COEF_SET0_DATA_2B))
+
/* legacy palette */
#define _LGC_PALETTE_A 0x4a000
#define _LGC_PALETTE_B 0x4a800
--
2.23.0

2020-02-25 07:33:14

by Daniel Stone

[permalink] [raw]

Subject: Re: [Intel-gfx] [RFC][PATCH 5/5] drm/i915/display: Add Nearest-neighbor based integer scaling support

Hi,

On Tue, 25 Feb 2020 at 07:17, Pankaj Bharadiya
<[email protected]> wrote:
> @@ -415,18 +415,26 @@ skl_program_scaler(struct intel_plane *plane,
> u16 y_vphase, uv_rgb_vphase;
> int hscale, vscale;
> const struct drm_plane_state *state = &plane_state->uapi;
> + u32 src_w = drm_rect_width(&plane_state->uapi.src) >> 16;
> + u32 src_h = drm_rect_height(&plane_state->uapi.src) >> 16;
> u32 scaling_filter = PS_FILTER_MEDIUM;
> + struct drm_rect dst;
>
> if (state->scaling_filter == DRM_SCALING_FILTER_NEAREST_NEIGHBOR) {
> scaling_filter = PS_FILTER_PROGRAMMED;
> + skl_setup_nearest_neighbor_filter(dev_priv, pipe, scaler_id);
> +
> + /* Make the scaling window size to integer multiple of source
> + * TODO: Should userspace take desision to round scaling window
> + * to integer multiple?
> + */
> + crtc_w = rounddown(crtc_w, src_w);
> + crtc_h = rounddown(crtc_h, src_h);

The kernel should absolutely not be changing the co-ordinates that
userspace requested.

Cheers,
Daniel

2020-02-28 05:50:44

by Laxminarayan Bharadiya, Pankaj

[permalink] [raw]

Subject: RE: [Intel-gfx] [RFC][PATCH 5/5] drm/i915/display: Add Nearest-neighbor based integer scaling support

> -----Original Message-----
> From: Daniel Stone <[email protected]>
> Sent: 25 February 2020 13:00
> To: Laxminarayan Bharadiya, Pankaj
> <[email protected]>
> Cc: Jani Nikula <[email protected]>; Daniel Vetter
> <[email protected]>; intel-gfx <[email protected]>; dri-devel
> <[email protected]>; Ville Syrjälä
> <[email protected]>; David Airlie <[email protected]>; Maarten
> Lankhorst <[email protected]>; [email protected];
> Maxime Ripard <[email protected]>; [email protected]; Joonas
> Lahtinen <[email protected]>; Vivi, Rodrigo
> <[email protected]>; Chris Wilson <[email protected]>; Souza,
> Jose <[email protected]>; De Marchi, Lucas
> <[email protected]>; Roper, Matthew D
> <[email protected]>; Deak, Imre <[email protected]>;
> Shankar, Uma <[email protected]>; Nautiyal, Ankit K
> <[email protected]>; Linux Kernel Mailing List <linux-
> [email protected]>
> Subject: Re: [Intel-gfx] [RFC][PATCH 5/5] drm/i915/display: Add Nearest-
> neighbor based integer scaling support
>
> Hi,
>
> On Tue, 25 Feb 2020 at 07:17, Pankaj Bharadiya
> <[email protected]> wrote:
> > @@ -415,18 +415,26 @@ skl_program_scaler(struct intel_plane *plane,
> > u16 y_vphase, uv_rgb_vphase;
> > int hscale, vscale;
> > const struct drm_plane_state *state = &plane_state->uapi;
> > + u32 src_w = drm_rect_width(&plane_state->uapi.src) >> 16;
> > + u32 src_h = drm_rect_height(&plane_state->uapi.src) >> 16;
> > u32 scaling_filter = PS_FILTER_MEDIUM;
> > + struct drm_rect dst;
> >
> > if (state->scaling_filter ==
> DRM_SCALING_FILTER_NEAREST_NEIGHBOR) {
> > scaling_filter = PS_FILTER_PROGRAMMED;
> > + skl_setup_nearest_neighbor_filter(dev_priv, pipe,
> > + scaler_id);
> > +
> > + /* Make the scaling window size to integer multiple of source
> > + * TODO: Should userspace take desision to round scaling window
> > + * to integer multiple?
> > + */
> > + crtc_w = rounddown(crtc_w, src_w);
> > + crtc_h = rounddown(crtc_h, src_h);
>
> The kernel should absolutely not be changing the co-ordinates that
> userspace requested.

Thanks, Will get rid of this in V2.

Thanks,
Pankaj
>
> Cheers,
> Daniel

2020-03-10 16:09:29

by Ville Syrjälä

[permalink] [raw]

Subject: Re: [RFC][PATCH 4/5] drm/i915: Introduce scaling filter related registers and bit fields.

On Tue, Feb 25, 2020 at 12:35:44PM +0530, Pankaj Bharadiya wrote:
> Introduce scaler registers and bit fields needed to configure the
> scaling filter in prgrammed mode and configure scaling filter
> coefficients.
>
> Signed-off-by: Pankaj Bharadiya <[email protected]>
> Signed-off-by: Ankit Nautiyal <[email protected]>
> ---
> drivers/gpu/drm/i915/i915_reg.h | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 34923b1c284c..bba4ad3be611 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -7289,6 +7289,18 @@ enum {
> #define _PS_ECC_STAT_2B 0x68AD0
> #define _PS_ECC_STAT_1C 0x691D0
>
> +#define _PS_COEF_SET0_INDEX_1A 0x68198
> +#define _PS_COEF_SET0_INDEX_2A 0x68298
> +#define _PS_COEF_SET0_INDEX_1B 0x68998
> +#define _PS_COEF_SET0_INDEX_2B 0x68A98
> +
> +#define _PS_COEF_SET0_DATA_1A 0x6819C
> +#define _PS_COEF_SET0_DATA_2A 0x6829C
> +#define _PS_COEF_SET0_DATA_1B 0x6899C
> +#define _PS_COEF_SET0_DATA_2B 0x68A9C
> +

Sourious whitespace.

> +#define _PS_COEE_INDEX_AUTO_INC (1 << 10)

Wrong indentation (though looks like most scaler register
definitions get that wrong already), and the leading '_' shouldn't
be here at all.

> +
> #define _ID(id, a, b) _PICK_EVEN(id, a, b)
> #define SKL_PS_CTRL(pipe, id) _MMIO_PIPE(pipe, \
> _ID(id, _PS_1A_CTRL, _PS_2A_CTRL), \
> @@ -7318,6 +7330,14 @@ enum {
> _ID(id, _PS_ECC_STAT_1A, _PS_ECC_STAT_2A), \
> _ID(id, _PS_ECC_STAT_1B, _PS_ECC_STAT_2B))
>
> +#define SKL_PS_COEF_INDEX_SET0(pipe, id) _MMIO_PIPE(pipe, \
> + _ID(id, _PS_COEF_SET0_INDEX_1A, _PS_COEF_SET0_INDEX_2A), \
> + _ID(id, _PS_COEF_SET0_INDEX_1B, _PS_COEF_SET0_INDEX_2B))
> +
> +#define SKL_PS_COEF_DATA_SET0(pipe, id) _MMIO_PIPE(pipe, \
> + _ID(id, _PS_COEF_SET0_DATA_1A, _PS_COEF_SET0_DATA_2A), \
> + _ID(id, _PS_COEF_SET0_DATA_1B, _PS_COEF_SET0_DATA_2B))

Please parametrize by 'set' as well.

> +
> /* legacy palette */
> #define _LGC_PALETTE_A 0x4a000
> #define _LGC_PALETTE_B 0x4a800
> --
> 2.23.0

--
Ville Syrj?l?
Intel

2020-03-10 16:09:53

by Ville Syrjälä

[permalink] [raw]

Subject: Re: [RFC][PATCH 3/5] drm/i915: Enable scaling filter for plane and pipe

On Tue, Feb 25, 2020 at 12:35:43PM +0530, Pankaj Bharadiya wrote:
> Attach scaling filter property for crtc and plane and program the
> scaler control register for the selected filter type.
>
> This is preparatory patch to enable Nearest-neighbor integer scaling.
>
> Signed-off-by: Pankaj Bharadiya <[email protected]>
> Signed-off-by: Ankit Nautiyal <[email protected]>
> ---
> drivers/gpu/drm/i915/display/intel_display.c | 17 +++++++++++++++--
> drivers/gpu/drm/i915/display/intel_sprite.c | 12 +++++++++++-
> drivers/gpu/drm/i915/i915_reg.h | 1 +
> 3 files changed, 27 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 3031e64ee518..b5903ef3c5a0 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -6242,6 +6242,8 @@ static void skl_pfit_enable(const struct intel_crtc_state *crtc_state)
> struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
> enum pipe pipe = crtc->pipe;
> + const struct drm_crtc_state *state = &crtc_state->uapi;
> + u32 scaling_filter = PS_FILTER_MEDIUM;
> const struct intel_crtc_scaler_state *scaler_state =
> &crtc_state->scaler_state;
>
> @@ -6258,6 +6260,11 @@ static void skl_pfit_enable(const struct intel_crtc_state *crtc_state)
> pfit_w = (crtc_state->pch_pfit.size >> 16) & 0xFFFF;
> pfit_h = crtc_state->pch_pfit.size & 0xFFFF;
>
> + if (state->scaling_filter ==
> + DRM_SCALING_FILTER_NEAREST_NEIGHBOR) {
> + scaling_filter = PS_FILTER_PROGRAMMED;
> + }

Just make that a function that can be used all over.
skl_scaler_filter(scaling_filter) or something.

> +
> hscale = (crtc_state->pipe_src_w << 16) / pfit_w;
> vscale = (crtc_state->pipe_src_h << 16) / pfit_h;
>
> @@ -6268,8 +6275,10 @@ static void skl_pfit_enable(const struct intel_crtc_state *crtc_state)
>
> spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
>
> - intel_de_write_fw(dev_priv, SKL_PS_CTRL(pipe, id), PS_SCALER_EN |
> - PS_FILTER_MEDIUM | scaler_state->scalers[id].mode);
> + intel_de_write_fw(dev_priv, SKL_PS_CTRL(pipe, id),
> + PS_SCALER_EN |
> + scaling_filter |
> + scaler_state->scalers[id].mode);
> intel_de_write_fw(dev_priv, SKL_PS_VPHASE(pipe, id),
> PS_Y_PHASE(0) | PS_UV_RGB_PHASE(uv_rgb_vphase));
> intel_de_write_fw(dev_priv, SKL_PS_HPHASE(pipe, id),
> @@ -16695,6 +16704,10 @@ static int intel_crtc_init(struct drm_i915_private *dev_priv, enum pipe pipe)
> dev_priv->plane_to_crtc_mapping[i9xx_plane] = crtc;
> }
>
> +
> + if (INTEL_GEN(dev_priv) >= 11)

gen >= 10 actually. Even glk seems to have it but bspec says not to
use it on glk. Supposedly not validated.

ilk/snb/ivb pfits also has programmable coefficients actually. So
IMO we should enable this on those as well.

The bigger problem will be how is userspace supposed to use this if it's
a crtc property? Those will not get automagically exposed via xrandr.

> + drm_crtc_enable_scaling_filter(&crtc->base);
> +
> intel_color_init(crtc);
>
> drm_WARN_ON(&dev_priv->drm, drm_crtc_index(&crtc->base) != crtc->pipe);
> diff --git a/drivers/gpu/drm/i915/display/intel_sprite.c b/drivers/gpu/drm/i915/display/intel_sprite.c
> index 7abeefe8dce5..fd7b31a21723 100644
> --- a/drivers/gpu/drm/i915/display/intel_sprite.c
> +++ b/drivers/gpu/drm/i915/display/intel_sprite.c
> @@ -414,6 +414,12 @@ skl_program_scaler(struct intel_plane *plane,
> u16 y_hphase, uv_rgb_hphase;
> u16 y_vphase, uv_rgb_vphase;
> int hscale, vscale;
> + const struct drm_plane_state *state = &plane_state->uapi;
> + u32 scaling_filter = PS_FILTER_MEDIUM;
> +
> + if (state->scaling_filter == DRM_SCALING_FILTER_NEAREST_NEIGHBOR) {
> + scaling_filter = PS_FILTER_PROGRAMMED;
> + }
>
> hscale = drm_rect_calc_hscale(&plane_state->uapi.src,
> &plane_state->uapi.dst,
> @@ -441,7 +447,8 @@ skl_program_scaler(struct intel_plane *plane,
> }
>
> intel_de_write_fw(dev_priv, SKL_PS_CTRL(pipe, scaler_id),
> - PS_SCALER_EN | PS_PLANE_SEL(plane->id) | scaler->mode);
> + scaling_filter | PS_SCALER_EN |
> + PS_PLANE_SEL(plane->id) | scaler->mode);
> intel_de_write_fw(dev_priv, SKL_PS_VPHASE(pipe, scaler_id),
> PS_Y_PHASE(y_vphase) | PS_UV_RGB_PHASE(uv_rgb_vphase));
> intel_de_write_fw(dev_priv, SKL_PS_HPHASE(pipe, scaler_id),
> @@ -3104,6 +3111,9 @@ skl_universal_plane_create(struct drm_i915_private *dev_priv,
>
> drm_plane_create_zpos_immutable_property(&plane->base, plane_id);
>
> + if (INTEL_GEN(dev_priv) >= 11)

also gen>=10

Also this patch breaks things as we don't yet have the code to program
the coefficients. So the series needs to be reordered.

> + drm_plane_enable_scaling_filter(&plane->base);
> +
> drm_plane_helper_add(&plane->base, &intel_plane_helper_funcs);
>
> return plane;
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index f45b5e86ec63..34923b1c284c 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -7212,6 +7212,7 @@ enum {
> #define PS_PLANE_SEL(plane) (((plane) + 1) << 25)
> #define PS_FILTER_MASK (3 << 23)
> #define PS_FILTER_MEDIUM (0 << 23)
> +#define PS_FILTER_PROGRAMMED (1 << 23)
> #define PS_FILTER_EDGE_ENHANCE (2 << 23)
> #define PS_FILTER_BILINEAR (3 << 23)
> #define PS_VERT3TAP (1 << 21)
> --
> 2.23.0

--
Ville Syrj?l?
Intel

2020-03-10 16:19:39

by Ville Syrjälä

[permalink] [raw]

Subject: Re: [RFC][PATCH 5/5] drm/i915/display: Add Nearest-neighbor based integer scaling support

On Tue, Feb 25, 2020 at 12:35:45PM +0530, Pankaj Bharadiya wrote:
> Integer scaling (IS) is a nearest-neighbor upscaling technique that
> simply scales up the existing pixels by an integer
> (i.e., whole number) multiplier.Nearest-neighbor (NN) interpolation
> works by filling in the missing color values in the upscaled image
> with that of the coordinate-mapped nearest source pixel value.
>
> Both IS and NN preserve the clarity of the original image. Integer
> scaling is particularly useful for pixel art games that rely on
> sharp, blocky images to deliver their distinctive look.
>
> Program the scaler filter coefficients to enable the NN filter if
> scaling filter property is set to DRM_SCALING_FILTER_NEAREST_NEIGHBOR
> and enable integer scaling.
>
> Bspec: 49247
>
> Signed-off-by: Pankaj Bharadiya <[email protected]>
> Signed-off-by: Ankit Nautiyal <[email protected]>
> ---
> drivers/gpu/drm/i915/display/intel_display.c | 83 +++++++++++++++++++-
> drivers/gpu/drm/i915/display/intel_display.h | 2 +
> drivers/gpu/drm/i915/display/intel_sprite.c | 20 +++--
> 3 files changed, 97 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index b5903ef3c5a0..6d5f59203258 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -6237,6 +6237,73 @@ void skl_scaler_disable(const struct intel_crtc_state *old_crtc_state)
> skl_detach_scaler(crtc, i);
> }
>
> +/**
> + * Theory behind setting nearest-neighbor integer scaling:
> + *
> + * 17 phase of 7 taps requires 119 coefficients in 60 dwords per set.
> + * The letter represents the filter tap (D is the center tap) and the number
> + * represents the coefficient set for a phase (0-16).
> + *
> + * +------------+------------------------+------------------------+
> + * |Index value | Data value coeffient 1 | Data value coeffient 2 |
> + * +------------+------------------------+------------------------+
> + * | 00h | B0 | A0 |
> + * +------------+------------------------+------------------------+
> + * | 01h | D0 | C0 |
> + * +------------+------------------------+------------------------+
> + * | 02h | F0 | E0 |
> + * +------------+------------------------+------------------------+
> + * | 03h | A1 | G0 |
> + * +------------+------------------------+------------------------+
> + * | 04h | C1 | B1 |
> + * +------------+------------------------+------------------------+
> + * | ... | ... | ... |
> + * +------------+------------------------+------------------------+
> + * | 38h | B16 | A16 |
> + * +------------+------------------------+------------------------+
> + * | 39h | D16 | C16 |
> + * +------------+------------------------+------------------------+
> + * | 3Ah | F16 | C16 |
> + * +------------+------------------------+------------------------+
> + * | 3Bh | Reserved | G16 |
> + * +------------+------------------------+------------------------+
> + *
> + * To enable nearest-neighbor scaling: program scaler coefficents with
> + * the center tap (Dxx) values set to 1 and all other values set to 0 as per
> + * SCALER_COEFFICIENT_FORMAT
> + *
> + */
> +void skl_setup_nearest_neighbor_filter(struct drm_i915_private *dev_priv,
> + enum pipe pipe, int scaler_id)

skl_scaler_...

> +{
> +
> + int coeff = 0;
> + int phase = 0;
> + int tap;
> + int val = 0;

Needlessly wide scope for most of these.

> +
> + /*enable the index auto increment.*/
> + intel_de_write_fw(dev_priv, SKL_PS_COEF_INDEX_SET0(pipe, scaler_id),
> + _PS_COEE_INDEX_AUTO_INC);
> +
> + for (phase = 0; phase < 17; phase++) {
> + for (tap = 0; tap < 7; tap++) {
> + coeff++;

Can be part of the % check.

> + if (tap == 3)
> + val = (phase % 2) ? (0x800) : (0x800 << 16);

Parens overload.

> +
> + if (coeff % 2 == 0) {
> + intel_de_write_fw(dev_priv, SKL_PS_COEF_DATA_SET0(pipe, scaler_id), val);
> + val = 0;

Can drop this val=0 if you move the variable into tight scope and
initialize there.

I was trying to think of a bit more generic way to do this, but couldn't
really think of anything apart from pre-filling the entire coefficient
set and the programming blindly. And that seems a bit wasteful if we only
care about nearest neighbour.

> + }
> +
> + }
> +
> + }
> +
> + intel_de_write_fw(dev_priv, SKL_PS_COEF_DATA_SET0(pipe, scaler_id), 0);
> +}
> +
> static void skl_pfit_enable(const struct intel_crtc_state *crtc_state)
> {
> struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> @@ -6260,9 +6327,23 @@ static void skl_pfit_enable(const struct intel_crtc_state *crtc_state)
> pfit_w = (crtc_state->pch_pfit.size >> 16) & 0xFFFF;
> pfit_h = crtc_state->pch_pfit.size & 0xFFFF;
>
> + id = scaler_state->scaler_id;
> +
> if (state->scaling_filter ==
> DRM_SCALING_FILTER_NEAREST_NEIGHBOR) {
> scaling_filter = PS_FILTER_PROGRAMMED;
> + skl_setup_nearest_neighbor_filter(dev_priv, pipe, id);

This should be sitting alongside the other register writes.

> +
> + /* Make the scaling window size to integer multiple of
> + * source.
> + *
> + * TODO: Should userspace take desision to round
> + * scaling window to integer multiple?

To give userspace actual control of the pfit window size we need the border
props (or something along those lines). Step 1 is
https://patchwork.freedesktop.org/series/68409/. There are further steps
in my branch after that, but it's still missing the border props for
eDP/LVDS/DSI since I was too lazy to think how they should interact with
the existing scaling mode prop.

> + */
> + pfit_w = rounddown(pfit_w,
> + (crtc_state->pipe_src_w << 16));
> + pfit_h = rounddown(pfit_h,
> + (crtc_state->pipe_src_h << 16));
> }

This part should be dropped as Daniel mentioned.

>
> hscale = (crtc_state->pipe_src_w << 16) / pfit_w;
> @@ -6271,8 +6352,6 @@ static void skl_pfit_enable(const struct intel_crtc_state *crtc_state)
> uv_rgb_hphase = skl_scaler_calc_phase(1, hscale, false);
> uv_rgb_vphase = skl_scaler_calc_phase(1, vscale, false);
>
> - id = scaler_state->scaler_id;
> -
> spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
>
> intel_de_write_fw(dev_priv, SKL_PS_CTRL(pipe, id),

I think we should also explicitly indicate here which cofficient set(s)
we're going to use, even if using set0 does mean those bits will be 0.

> diff --git a/drivers/gpu/drm/i915/display/intel_display.h b/drivers/gpu/drm/i915/display/intel_display.h
> index f92efbbec838..49f58d3c98fe 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.h
> +++ b/drivers/gpu/drm/i915/display/intel_display.h
> @@ -586,6 +586,8 @@ void intel_crtc_arm_fifo_underrun(struct intel_crtc *crtc,
> u16 skl_scaler_calc_phase(int sub, int scale, bool chroma_center);
> int skl_update_scaler_crtc(struct intel_crtc_state *crtc_state);
> void skl_scaler_disable(const struct intel_crtc_state *old_crtc_state);
> +void skl_setup_nearest_neighbor_filter(struct drm_i915_private *dev_priv,
> + enum pipe pipe, int scaler_id);
> void ilk_pfit_disable(const struct intel_crtc_state *old_crtc_state);
> u32 glk_plane_color_ctl(const struct intel_crtc_state *crtc_state,
> const struct intel_plane_state *plane_state);
> diff --git a/drivers/gpu/drm/i915/display/intel_sprite.c b/drivers/gpu/drm/i915/display/intel_sprite.c
> index fd7b31a21723..5bef5c031374 100644
> --- a/drivers/gpu/drm/i915/display/intel_sprite.c
> +++ b/drivers/gpu/drm/i915/display/intel_sprite.c
> @@ -415,18 +415,26 @@ skl_program_scaler(struct intel_plane *plane,
> u16 y_vphase, uv_rgb_vphase;
> int hscale, vscale;
> const struct drm_plane_state *state = &plane_state->uapi;
> + u32 src_w = drm_rect_width(&plane_state->uapi.src) >> 16;
> + u32 src_h = drm_rect_height(&plane_state->uapi.src) >> 16;
> u32 scaling_filter = PS_FILTER_MEDIUM;
> + struct drm_rect dst;
>
> if (state->scaling_filter == DRM_SCALING_FILTER_NEAREST_NEIGHBOR) {
> scaling_filter = PS_FILTER_PROGRAMMED;
> + skl_setup_nearest_neighbor_filter(dev_priv, pipe, scaler_id);
> +
> + /* Make the scaling window size to integer multiple of source
> + * TODO: Should userspace take desision to round scaling window
> + * to integer multiple?
> + */
> + crtc_w = rounddown(crtc_w, src_w);
> + crtc_h = rounddown(crtc_h, src_h);
> }
>
> - hscale = drm_rect_calc_hscale(&plane_state->uapi.src,
> - &plane_state->uapi.dst,
> - 0, INT_MAX);
> - vscale = drm_rect_calc_vscale(&plane_state->uapi.src,
> - &plane_state->uapi.dst,
> - 0, INT_MAX);
> + drm_rect_init(&dst, crtc_x, crtc_y, crtc_w, crtc_h);

Drop as well.

> + hscale = drm_rect_calc_hscale(&plane_state->uapi.src, &dst, 0, INT_MAX);
> + vscale = drm_rect_calc_vscale(&plane_state->uapi.src, &dst, 0, INT_MAX);
>
> /* TODO: handle sub-pixel coordinates */
> if (intel_format_info_is_yuv_semiplanar(fb->format, fb->modifier) &&
> --
> 2.23.0

--
Ville Syrj?l?
Intel

2020-03-12 08:59:28

by Laxminarayan Bharadiya, Pankaj

[permalink] [raw]

Subject: RE: [RFC][PATCH 3/5] drm/i915: Enable scaling filter for plane and pipe

> -----Original Message-----
> From: Ville Syrj?l? <[email protected]>
> Sent: 10 March 2020 21:36
> To: Laxminarayan Bharadiya, Pankaj
> <[email protected]>
> Cc: [email protected]; [email protected]; intel-
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected];
> [email protected]; [email protected]; Joonas Lahtinen
> <[email protected]>; Vivi, Rodrigo <[email protected]>;
> Chris Wilson <[email protected]>; Souza, Jose
> <[email protected]>; Juha-Pekka Heikkila
> <[email protected]>; [email protected]; Nautiyal,
> Ankit K <[email protected]>
> Subject: Re: [RFC][PATCH 3/5] drm/i915: Enable scaling filter for plane and
> pipe
>
> On Tue, Feb 25, 2020 at 12:35:43PM +0530, Pankaj Bharadiya wrote:
> > Attach scaling filter property for crtc and plane and program the
> > scaler control register for the selected filter type.
> >
> > This is preparatory patch to enable Nearest-neighbor integer scaling.
> >
> > Signed-off-by: Pankaj Bharadiya
> > <[email protected]>
> > Signed-off-by: Ankit Nautiyal <[email protected]>
> > ---
> > drivers/gpu/drm/i915/display/intel_display.c | 17 +++++++++++++++--
> > drivers/gpu/drm/i915/display/intel_sprite.c | 12 +++++++++++-
> > drivers/gpu/drm/i915/i915_reg.h | 1 +
> > 3 files changed, 27 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_display.c
> > b/drivers/gpu/drm/i915/display/intel_display.c
> > index 3031e64ee518..b5903ef3c5a0 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > @@ -6242,6 +6242,8 @@ static void skl_pfit_enable(const struct
> intel_crtc_state *crtc_state)
> > struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> > struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
> > enum pipe pipe = crtc->pipe;
> > + const struct drm_crtc_state *state = &crtc_state->uapi;
> > + u32 scaling_filter = PS_FILTER_MEDIUM;
> > const struct intel_crtc_scaler_state *scaler_state =
> > &crtc_state->scaler_state;
> >
> > @@ -6258,6 +6260,11 @@ static void skl_pfit_enable(const struct
> intel_crtc_state *crtc_state)
> > pfit_w = (crtc_state->pch_pfit.size >> 16) & 0xFFFF;
> > pfit_h = crtc_state->pch_pfit.size & 0xFFFF;
> >
> > + if (state->scaling_filter ==
> > + DRM_SCALING_FILTER_NEAREST_NEIGHBOR) {
> > + scaling_filter = PS_FILTER_PROGRAMMED;
> > + }
>
> Just make that a function that can be used all over.
> skl_scaler_filter(scaling_filter) or something.
>
> > +
> > hscale = (crtc_state->pipe_src_w << 16) / pfit_w;
> > vscale = (crtc_state->pipe_src_h << 16) / pfit_h;
> >
> > @@ -6268,8 +6275,10 @@ static void skl_pfit_enable(const struct
> > intel_crtc_state *crtc_state)
> >
> > spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
> >
> > - intel_de_write_fw(dev_priv, SKL_PS_CTRL(pipe, id),
> PS_SCALER_EN |
> > - PS_FILTER_MEDIUM | scaler_state-
> >scalers[id].mode);
> > + intel_de_write_fw(dev_priv, SKL_PS_CTRL(pipe, id),
> > + PS_SCALER_EN |
> > + scaling_filter |
> > + scaler_state->scalers[id].mode);
> > intel_de_write_fw(dev_priv, SKL_PS_VPHASE(pipe, id),
> > PS_Y_PHASE(0) |
> PS_UV_RGB_PHASE(uv_rgb_vphase));
> > intel_de_write_fw(dev_priv, SKL_PS_HPHASE(pipe, id), @@
> -16695,6
> > +16704,10 @@ static int intel_crtc_init(struct drm_i915_private *dev_priv,
> enum pipe pipe)
> > dev_priv->plane_to_crtc_mapping[i9xx_plane] = crtc;
> > }
> >
> > +
> > + if (INTEL_GEN(dev_priv) >= 11)
>
> gen >= 10 actually. Even glk seems to have it but bspec says not to use it on
> glk. Supposedly not validated.
>
> ilk/snb/ivb pfits also has programmable coefficients actually. So IMO we
> should enable this on those as well.

OK. I need to explore bspec more for these platforms.
To begin with I would like to stick to gen >=10.

>
> The bigger problem will be how is userspace supposed to use this if it's a crtc
> property? Those will not get automagically exposed via xrandr.
>
> > + drm_crtc_enable_scaling_filter(&crtc->base);
> > +
> > intel_color_init(crtc);
> >
> > drm_WARN_ON(&dev_priv->drm, drm_crtc_index(&crtc->base) !=
> > crtc->pipe); diff --git a/drivers/gpu/drm/i915/display/intel_sprite.c
> > b/drivers/gpu/drm/i915/display/intel_sprite.c
> > index 7abeefe8dce5..fd7b31a21723 100644
> > --- a/drivers/gpu/drm/i915/display/intel_sprite.c
> > +++ b/drivers/gpu/drm/i915/display/intel_sprite.c
> > @@ -414,6 +414,12 @@ skl_program_scaler(struct intel_plane *plane,
> > u16 y_hphase, uv_rgb_hphase;
> > u16 y_vphase, uv_rgb_vphase;
> > int hscale, vscale;
> > + const struct drm_plane_state *state = &plane_state->uapi;
> > + u32 scaling_filter = PS_FILTER_MEDIUM;
> > +
> > + if (state->scaling_filter ==
> DRM_SCALING_FILTER_NEAREST_NEIGHBOR) {
> > + scaling_filter = PS_FILTER_PROGRAMMED;
> > + }
> >
> > hscale = drm_rect_calc_hscale(&plane_state->uapi.src,
> > &plane_state->uapi.dst,
> > @@ -441,7 +447,8 @@ skl_program_scaler(struct intel_plane *plane,
> > }
> >
> > intel_de_write_fw(dev_priv, SKL_PS_CTRL(pipe, scaler_id),
> > - PS_SCALER_EN | PS_PLANE_SEL(plane->id) | scaler-
> >mode);
> > + scaling_filter | PS_SCALER_EN |
> > + PS_PLANE_SEL(plane->id) | scaler->mode);
> > intel_de_write_fw(dev_priv, SKL_PS_VPHASE(pipe, scaler_id),
> > PS_Y_PHASE(y_vphase) |
> PS_UV_RGB_PHASE(uv_rgb_vphase));
> > intel_de_write_fw(dev_priv, SKL_PS_HPHASE(pipe, scaler_id), @@
> > -3104,6 +3111,9 @@ skl_universal_plane_create(struct drm_i915_private
> > *dev_priv,
> >
> > drm_plane_create_zpos_immutable_property(&plane->base,
> plane_id);
> >
> > + if (INTEL_GEN(dev_priv) >= 11)
>
> also gen>=10
>
> Also this patch breaks things as we don't yet have the code to program the
> coefficients. So the series needs to be reordered.

Will reorder the series.

Thanks,
Pankaj
>
> > + drm_plane_enable_scaling_filter(&plane->base);
> > +
> > drm_plane_helper_add(&plane->base, &intel_plane_helper_funcs);
> >
> > return plane;
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h
> > b/drivers/gpu/drm/i915/i915_reg.h index f45b5e86ec63..34923b1c284c
> > 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -7212,6 +7212,7 @@ enum {
> > #define PS_PLANE_SEL(plane) (((plane) + 1) << 25)
> > #define PS_FILTER_MASK (3 << 23)
> > #define PS_FILTER_MEDIUM (0 << 23)
> > +#define PS_FILTER_PROGRAMMED (1 << 23)
> > #define PS_FILTER_EDGE_ENHANCE (2 << 23)
> > #define PS_FILTER_BILINEAR (3 << 23)
> > #define PS_VERT3TAP (1 << 21)
> > --
> > 2.23.0
>
> --
> Ville Syrj?l?
> Intel

2020-03-12 09:14:01

by Laxminarayan Bharadiya, Pankaj

[permalink] [raw]

Subject: RE: [RFC][PATCH 5/5] drm/i915/display: Add Nearest-neighbor based integer scaling support

> -----Original Message-----
> From: Ville Syrj?l? <[email protected]>
> Sent: 10 March 2020 21:47
> To: Laxminarayan Bharadiya, Pankaj
> <[email protected]>
> Cc: [email protected]; [email protected]; intel-
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected];
> [email protected]; [email protected]; Joonas Lahtinen
> <[email protected]>; Vivi, Rodrigo <[email protected]>;
> Chris Wilson <[email protected]>; Souza, Jose
> <[email protected]>; De Marchi, Lucas <[email protected]>;
> Roper, Matthew D <[email protected]>; Deak, Imre
> <[email protected]>; Shankar, Uma <[email protected]>; linux-
> [email protected]; Nautiyal, Ankit K <[email protected]>
> Subject: Re: [RFC][PATCH 5/5] drm/i915/display: Add Nearest-neighbor
> based integer scaling support
>
> On Tue, Feb 25, 2020 at 12:35:45PM +0530, Pankaj Bharadiya wrote:
> > Integer scaling (IS) is a nearest-neighbor upscaling technique that
> > simply scales up the existing pixels by an integer (i.e., whole
> > number) multiplier.Nearest-neighbor (NN) interpolation works by
> > filling in the missing color values in the upscaled image with that of
> > the coordinate-mapped nearest source pixel value.
> >
> > Both IS and NN preserve the clarity of the original image. Integer
> > scaling is particularly useful for pixel art games that rely on sharp,
> > blocky images to deliver their distinctive look.
> >
> > Program the scaler filter coefficients to enable the NN filter if
> > scaling filter property is set to DRM_SCALING_FILTER_NEAREST_NEIGHBOR
> > and enable integer scaling.
> >
> > Bspec: 49247
> >
> > Signed-off-by: Pankaj Bharadiya
> > <[email protected]>
> > Signed-off-by: Ankit Nautiyal <[email protected]>
> > ---
> > drivers/gpu/drm/i915/display/intel_display.c | 83
> > +++++++++++++++++++- drivers/gpu/drm/i915/display/intel_display.h |
> > 2 + drivers/gpu/drm/i915/display/intel_sprite.c | 20 +++--
> > 3 files changed, 97 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_display.c
> > b/drivers/gpu/drm/i915/display/intel_display.c
> > index b5903ef3c5a0..6d5f59203258 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > @@ -6237,6 +6237,73 @@ void skl_scaler_disable(const struct
> intel_crtc_state *old_crtc_state)
> > skl_detach_scaler(crtc, i);
> > }
> >
> > +/**
> > + * Theory behind setting nearest-neighbor integer scaling:
> > + *
> > + * 17 phase of 7 taps requires 119 coefficients in 60 dwords per set.
> > + * The letter represents the filter tap (D is the center tap) and
> > +the number
> > + * represents the coefficient set for a phase (0-16).
> > + *
> > + * +------------+------------------------+------------------------+
> > + * |Index value | Data value coeffient 1 | Data value coeffient 2 |
> > + * +------------+------------------------+------------------------+
> > + * | 00h | B0 | A0 |
> > + * +------------+------------------------+------------------------+
> > + * | 01h | D0 | C0 |
> > + * +------------+------------------------+------------------------+
> > + * | 02h | F0 | E0 |
> > + * +------------+------------------------+------------------------+
> > + * | 03h | A1 | G0 |
> > + * +------------+------------------------+------------------------+
> > + * | 04h | C1 | B1 |
> > + * +------------+------------------------+------------------------+
> > + * | ... | ... | ... |
> > + * +------------+------------------------+------------------------+
> > + * | 38h | B16 | A16 |
> > + * +------------+------------------------+------------------------+
> > + * | 39h | D16 | C16 |
> > + * +------------+------------------------+------------------------+
> > + * | 3Ah | F16 | C16 |
> > + * +------------+------------------------+------------------------+
> > + * | 3Bh | Reserved | G16 |
> > + * +------------+------------------------+------------------------+
> > + *
> > + * To enable nearest-neighbor scaling: program scaler coefficents
> > +with
> > + * the center tap (Dxx) values set to 1 and all other values set to
> > +0 as per
> > + * SCALER_COEFFICIENT_FORMAT
> > + *
> > + */
> > +void skl_setup_nearest_neighbor_filter(struct drm_i915_private
> *dev_priv,
> > + enum pipe pipe, int scaler_id)
>
> skl_scaler_...
>
> > +{
> > +
> > + int coeff = 0;
> > + int phase = 0;
> > + int tap;
> > + int val = 0;
>
> Needlessly wide scope for most of these.
>
> > +
> > + /*enable the index auto increment.*/
> > + intel_de_write_fw(dev_priv, SKL_PS_COEF_INDEX_SET0(pipe,
> scaler_id),
> > + _PS_COEE_INDEX_AUTO_INC);
> > +
> > + for (phase = 0; phase < 17; phase++) {
> > + for (tap = 0; tap < 7; tap++) {
> > + coeff++;
>
> Can be part of the % check.

OK.

>
> > + if (tap == 3)
> > + val = (phase % 2) ? (0x800) : (0x800 << 16);
>
> Parens overload.

OK. Will remove.
>
> > +
> > + if (coeff % 2 == 0) {
> > + intel_de_write_fw(dev_priv,
> SKL_PS_COEF_DATA_SET0(pipe, scaler_id), val);
> > + val = 0;
>
> Can drop this val=0 if you move the variable into tight scope and initialize
> there.

Moving val=0 initialization to the tight scope will not work here as we need
to retain "val" and write only when 2 coefficients are ready (since 2
coefficients are packed in 1 dword).

e.g. for (12th , 11th) coefficients, coefficient reg value should be ( (0 << 16) | 0x800).
If we initialize val = 0 in tight loop, 0 will be written to coefficient register.

>
> I was trying to think of a bit more generic way to do this, but couldn't really
> think of anything apart from pre-filling the entire coefficient set and the
> programming blindly. And that seems a bit wasteful if we only care about
> nearest neighbour.
>
> > + }
> > +
> > + }
> > +
> > + }
> > +
> > + intel_de_write_fw(dev_priv, SKL_PS_COEF_DATA_SET0(pipe,
> scaler_id),
> > +0); }
> > +
> > static void skl_pfit_enable(const struct intel_crtc_state
> > *crtc_state) {
> > struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> > @@ -6260,9 +6327,23 @@ static void skl_pfit_enable(const struct
> intel_crtc_state *crtc_state)
> > pfit_w = (crtc_state->pch_pfit.size >> 16) & 0xFFFF;
> > pfit_h = crtc_state->pch_pfit.size & 0xFFFF;
> >
> > + id = scaler_state->scaler_id;
> > +
> > if (state->scaling_filter ==
> > DRM_SCALING_FILTER_NEAREST_NEIGHBOR) {
> > scaling_filter = PS_FILTER_PROGRAMMED;
> > + skl_setup_nearest_neighbor_filter(dev_priv, pipe,
> id);
>
> This should be sitting alongside the other register writes.

I missed this, thanks for pointing out.

>
> > +
> > + /* Make the scaling window size to integer multiple
> of
> > + * source.
> > + *
> > + * TODO: Should userspace take desision to round
> > + * scaling window to integer multiple?
>
> To give userspace actual control of the pfit window size we need the border
> props (or something along those lines). Step 1 is
> https://patchwork.freedesktop.org/series/68409/. There are further steps in
> my branch after that, but it's still missing the border props for eDP/LVDS/DSI
> since I was too lazy to think how they should interact with the existing scaling
> mode prop.
>
> > + */
> > + pfit_w = rounddown(pfit_w,
> > + (crtc_state->pipe_src_w << 16));
> > + pfit_h = rounddown(pfit_h,
> > + (crtc_state->pipe_src_h << 16));
> > }
>
> This part should be dropped as Daniel mentioned.

Will remove.

Thanks,
Pankaj

>
> >
> > hscale = (crtc_state->pipe_src_w << 16) / pfit_w; @@ -
> 6271,8
> > +6352,6 @@ static void skl_pfit_enable(const struct intel_crtc_state
> *crtc_state)
> > uv_rgb_hphase = skl_scaler_calc_phase(1, hscale, false);
> > uv_rgb_vphase = skl_scaler_calc_phase(1, vscale, false);
> >
> > - id = scaler_state->scaler_id;
> > -
> > spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
> >
> > intel_de_write_fw(dev_priv, SKL_PS_CTRL(pipe, id),
>
> I think we should also explicitly indicate here which cofficient set(s) we're
> going to use, even if using set0 does mean those bits will be 0.
>
> > diff --git a/drivers/gpu/drm/i915/display/intel_display.h
> > b/drivers/gpu/drm/i915/display/intel_display.h
> > index f92efbbec838..49f58d3c98fe 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display.h
> > +++ b/drivers/gpu/drm/i915/display/intel_display.h
> > @@ -586,6 +586,8 @@ void intel_crtc_arm_fifo_underrun(struct
> > intel_crtc *crtc,
> > u16 skl_scaler_calc_phase(int sub, int scale, bool chroma_center);
> > int skl_update_scaler_crtc(struct intel_crtc_state *crtc_state); void
> > skl_scaler_disable(const struct intel_crtc_state *old_crtc_state);
> > +void skl_setup_nearest_neighbor_filter(struct drm_i915_private
> *dev_priv,
> > + enum pipe pipe, int scaler_id);
> > void ilk_pfit_disable(const struct intel_crtc_state *old_crtc_state);
> > u32 glk_plane_color_ctl(const struct intel_crtc_state *crtc_state,
> > const struct intel_plane_state *plane_state); diff --
> git
> > a/drivers/gpu/drm/i915/display/intel_sprite.c
> > b/drivers/gpu/drm/i915/display/intel_sprite.c
> > index fd7b31a21723..5bef5c031374 100644
> > --- a/drivers/gpu/drm/i915/display/intel_sprite.c
> > +++ b/drivers/gpu/drm/i915/display/intel_sprite.c
> > @@ -415,18 +415,26 @@ skl_program_scaler(struct intel_plane *plane,
> > u16 y_vphase, uv_rgb_vphase;
> > int hscale, vscale;
> > const struct drm_plane_state *state = &plane_state->uapi;
> > + u32 src_w = drm_rect_width(&plane_state->uapi.src) >> 16;
> > + u32 src_h = drm_rect_height(&plane_state->uapi.src) >> 16;
> > u32 scaling_filter = PS_FILTER_MEDIUM;
> > + struct drm_rect dst;
> >
> > if (state->scaling_filter ==
> DRM_SCALING_FILTER_NEAREST_NEIGHBOR) {
> > scaling_filter = PS_FILTER_PROGRAMMED;
> > + skl_setup_nearest_neighbor_filter(dev_priv, pipe,
> scaler_id);
> > +
> > + /* Make the scaling window size to integer multiple of source
> > + * TODO: Should userspace take desision to round scaling
> window
> > + * to integer multiple?
> > + */
> > + crtc_w = rounddown(crtc_w, src_w);
> > + crtc_h = rounddown(crtc_h, src_h);
> > }
> >
> > - hscale = drm_rect_calc_hscale(&plane_state->uapi.src,
> > - &plane_state->uapi.dst,
> > - 0, INT_MAX);
> > - vscale = drm_rect_calc_vscale(&plane_state->uapi.src,
> > - &plane_state->uapi.dst,
> > - 0, INT_MAX);
> > + drm_rect_init(&dst, crtc_x, crtc_y, crtc_w, crtc_h);
>
> Drop as well.
>
> > + hscale = drm_rect_calc_hscale(&plane_state->uapi.src, &dst, 0,
> INT_MAX);
> > + vscale = drm_rect_calc_vscale(&plane_state->uapi.src, &dst, 0,
> > +INT_MAX);
> >
> > /* TODO: handle sub-pixel coordinates */
> > if (intel_format_info_is_yuv_semiplanar(fb->format, fb->modifier)
> &&
> > --
> > 2.23.0
>
> --
> Ville Syrj?l?
> Intel

2020-03-12 12:28:28

by Ville Syrjälä

[permalink] [raw]

Subject: Re: [RFC][PATCH 3/5] drm/i915: Enable scaling filter for plane and pipe

On Thu, Mar 12, 2020 at 08:58:42AM +0000, Laxminarayan Bharadiya, Pankaj wrote:
>
>
> > -----Original Message-----
> > From: Ville Syrj?l? <[email protected]>
> > Sent: 10 March 2020 21:36
> > To: Laxminarayan Bharadiya, Pankaj
> > <[email protected]>
> > Cc: [email protected]; [email protected]; intel-
> > [email protected]; [email protected]; [email protected];
> > [email protected]; [email protected];
> > [email protected]; [email protected]; Joonas Lahtinen
> > <[email protected]>; Vivi, Rodrigo <[email protected]>;
> > Chris Wilson <[email protected]>; Souza, Jose
> > <[email protected]>; Juha-Pekka Heikkila
> > <[email protected]>; [email protected]; Nautiyal,
> > Ankit K <[email protected]>
> > Subject: Re: [RFC][PATCH 3/5] drm/i915: Enable scaling filter for plane and
> > pipe
> >
> > On Tue, Feb 25, 2020 at 12:35:43PM +0530, Pankaj Bharadiya wrote:
> > > Attach scaling filter property for crtc and plane and program the
> > > scaler control register for the selected filter type.
> > >
> > > This is preparatory patch to enable Nearest-neighbor integer scaling.
> > >
> > > Signed-off-by: Pankaj Bharadiya
> > > <[email protected]>
> > > Signed-off-by: Ankit Nautiyal <[email protected]>
> > > ---
> > > drivers/gpu/drm/i915/display/intel_display.c | 17 +++++++++++++++--
> > > drivers/gpu/drm/i915/display/intel_sprite.c | 12 +++++++++++-
> > > drivers/gpu/drm/i915/i915_reg.h | 1 +
> > > 3 files changed, 27 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/i915/display/intel_display.c
> > > b/drivers/gpu/drm/i915/display/intel_display.c
> > > index 3031e64ee518..b5903ef3c5a0 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > > @@ -6242,6 +6242,8 @@ static void skl_pfit_enable(const struct
> > intel_crtc_state *crtc_state)
> > > struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> > > struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
> > > enum pipe pipe = crtc->pipe;
> > > + const struct drm_crtc_state *state = &crtc_state->uapi;
> > > + u32 scaling_filter = PS_FILTER_MEDIUM;
> > > const struct intel_crtc_scaler_state *scaler_state =
> > > &crtc_state->scaler_state;
> > >
> > > @@ -6258,6 +6260,11 @@ static void skl_pfit_enable(const struct
> > intel_crtc_state *crtc_state)
> > > pfit_w = (crtc_state->pch_pfit.size >> 16) & 0xFFFF;
> > > pfit_h = crtc_state->pch_pfit.size & 0xFFFF;
> > >
> > > + if (state->scaling_filter ==
> > > + DRM_SCALING_FILTER_NEAREST_NEIGHBOR) {
> > > + scaling_filter = PS_FILTER_PROGRAMMED;
> > > + }
> >
> > Just make that a function that can be used all over.
> > skl_scaler_filter(scaling_filter) or something.
> >
> > > +
> > > hscale = (crtc_state->pipe_src_w << 16) / pfit_w;
> > > vscale = (crtc_state->pipe_src_h << 16) / pfit_h;
> > >
> > > @@ -6268,8 +6275,10 @@ static void skl_pfit_enable(const struct
> > > intel_crtc_state *crtc_state)
> > >
> > > spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
> > >
> > > - intel_de_write_fw(dev_priv, SKL_PS_CTRL(pipe, id),
> > PS_SCALER_EN |
> > > - PS_FILTER_MEDIUM | scaler_state-
> > >scalers[id].mode);
> > > + intel_de_write_fw(dev_priv, SKL_PS_CTRL(pipe, id),
> > > + PS_SCALER_EN |
> > > + scaling_filter |
> > > + scaler_state->scalers[id].mode);
> > > intel_de_write_fw(dev_priv, SKL_PS_VPHASE(pipe, id),
> > > PS_Y_PHASE(0) |
> > PS_UV_RGB_PHASE(uv_rgb_vphase));
> > > intel_de_write_fw(dev_priv, SKL_PS_HPHASE(pipe, id), @@
> > -16695,6
> > > +16704,10 @@ static int intel_crtc_init(struct drm_i915_private *dev_priv,
> > enum pipe pipe)
> > > dev_priv->plane_to_crtc_mapping[i9xx_plane] = crtc;
> > > }
> > >
> > > +
> > > + if (INTEL_GEN(dev_priv) >= 11)
> >
> > gen >= 10 actually. Even glk seems to have it but bspec says not to use it on
> > glk. Supposedly not validated.
> >
> > ilk/snb/ivb pfits also has programmable coefficients actually. So IMO we
> > should enable this on those as well.
>
> OK. I need to explore bspec more for these platforms.
> To begin with I would like to stick to gen >=10.

Sure. You can also have a look at the intel_scaling_coef hacks I posted
to igt-dev for details on how to drive them all. I already reverse
engineered them sufficiently so that I was able to program them ;)

>
> >
> > The bigger problem will be how is userspace supposed to use this if it's a crtc
> > property? Those will not get automagically exposed via xrandr.
> >
> > > + drm_crtc_enable_scaling_filter(&crtc->base);
> > > +
> > > intel_color_init(crtc);
> > >
> > > drm_WARN_ON(&dev_priv->drm, drm_crtc_index(&crtc->base) !=
> > > crtc->pipe); diff --git a/drivers/gpu/drm/i915/display/intel_sprite.c
> > > b/drivers/gpu/drm/i915/display/intel_sprite.c
> > > index 7abeefe8dce5..fd7b31a21723 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_sprite.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_sprite.c
> > > @@ -414,6 +414,12 @@ skl_program_scaler(struct intel_plane *plane,
> > > u16 y_hphase, uv_rgb_hphase;
> > > u16 y_vphase, uv_rgb_vphase;
> > > int hscale, vscale;
> > > + const struct drm_plane_state *state = &plane_state->uapi;
> > > + u32 scaling_filter = PS_FILTER_MEDIUM;
> > > +
> > > + if (state->scaling_filter ==
> > DRM_SCALING_FILTER_NEAREST_NEIGHBOR) {
> > > + scaling_filter = PS_FILTER_PROGRAMMED;
> > > + }
> > >
> > > hscale = drm_rect_calc_hscale(&plane_state->uapi.src,
> > > &plane_state->uapi.dst,
> > > @@ -441,7 +447,8 @@ skl_program_scaler(struct intel_plane *plane,
> > > }
> > >
> > > intel_de_write_fw(dev_priv, SKL_PS_CTRL(pipe, scaler_id),
> > > - PS_SCALER_EN | PS_PLANE_SEL(plane->id) | scaler-
> > >mode);
> > > + scaling_filter | PS_SCALER_EN |
> > > + PS_PLANE_SEL(plane->id) | scaler->mode);
> > > intel_de_write_fw(dev_priv, SKL_PS_VPHASE(pipe, scaler_id),
> > > PS_Y_PHASE(y_vphase) |
> > PS_UV_RGB_PHASE(uv_rgb_vphase));
> > > intel_de_write_fw(dev_priv, SKL_PS_HPHASE(pipe, scaler_id), @@
> > > -3104,6 +3111,9 @@ skl_universal_plane_create(struct drm_i915_private
> > > *dev_priv,
> > >
> > > drm_plane_create_zpos_immutable_property(&plane->base,
> > plane_id);
> > >
> > > + if (INTEL_GEN(dev_priv) >= 11)
> >
> > also gen>=10
> >
> > Also this patch breaks things as we don't yet have the code to program the
> > coefficients. So the series needs to be reordered.
>
> Will reorder the series.
>
> Thanks,
> Pankaj
> >
> > > + drm_plane_enable_scaling_filter(&plane->base);
> > > +
> > > drm_plane_helper_add(&plane->base, &intel_plane_helper_funcs);
> > >
> > > return plane;
> > > diff --git a/drivers/gpu/drm/i915/i915_reg.h
> > > b/drivers/gpu/drm/i915/i915_reg.h index f45b5e86ec63..34923b1c284c
> > > 100644
> > > --- a/drivers/gpu/drm/i915/i915_reg.h
> > > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > > @@ -7212,6 +7212,7 @@ enum {
> > > #define PS_PLANE_SEL(plane) (((plane) + 1) << 25)
> > > #define PS_FILTER_MASK (3 << 23)
> > > #define PS_FILTER_MEDIUM (0 << 23)
> > > +#define PS_FILTER_PROGRAMMED (1 << 23)
> > > #define PS_FILTER_EDGE_ENHANCE (2 << 23)
> > > #define PS_FILTER_BILINEAR (3 << 23)
> > > #define PS_VERT3TAP (1 << 21)
> > > --
> > > 2.23.0
> >
> > --
> > Ville Syrj?l?
> > Intel

--
Ville Syrj?l?
Intel

2020-03-12 13:55:20

by Ville Syrjälä

[permalink] [raw]

Subject: Re: [RFC][PATCH 5/5] drm/i915/display: Add Nearest-neighbor based integer scaling support

On Thu, Mar 12, 2020 at 09:13:24AM +0000, Laxminarayan Bharadiya, Pankaj wrote:
>
>
> > -----Original Message-----
> > From: Ville Syrj?l? <[email protected]>
> > Sent: 10 March 2020 21:47
> > To: Laxminarayan Bharadiya, Pankaj
> > <[email protected]>
> > Cc: [email protected]; [email protected]; intel-
> > [email protected]; [email protected]; [email protected];
> > [email protected]; [email protected];
> > [email protected]; [email protected]; Joonas Lahtinen
> > <[email protected]>; Vivi, Rodrigo <[email protected]>;
> > Chris Wilson <[email protected]>; Souza, Jose
> > <[email protected]>; De Marchi, Lucas <[email protected]>;
> > Roper, Matthew D <[email protected]>; Deak, Imre
> > <[email protected]>; Shankar, Uma <[email protected]>; linux-
> > [email protected]; Nautiyal, Ankit K <[email protected]>
> > Subject: Re: [RFC][PATCH 5/5] drm/i915/display: Add Nearest-neighbor
> > based integer scaling support
> >
> > On Tue, Feb 25, 2020 at 12:35:45PM +0530, Pankaj Bharadiya wrote:
> > > Integer scaling (IS) is a nearest-neighbor upscaling technique that
> > > simply scales up the existing pixels by an integer (i.e., whole
> > > number) multiplier.Nearest-neighbor (NN) interpolation works by
> > > filling in the missing color values in the upscaled image with that of
> > > the coordinate-mapped nearest source pixel value.
> > >
> > > Both IS and NN preserve the clarity of the original image. Integer
> > > scaling is particularly useful for pixel art games that rely on sharp,
> > > blocky images to deliver their distinctive look.
> > >
> > > Program the scaler filter coefficients to enable the NN filter if
> > > scaling filter property is set to DRM_SCALING_FILTER_NEAREST_NEIGHBOR
> > > and enable integer scaling.
> > >
> > > Bspec: 49247
> > >
> > > Signed-off-by: Pankaj Bharadiya
> > > <[email protected]>
> > > Signed-off-by: Ankit Nautiyal <[email protected]>
> > > ---
> > > drivers/gpu/drm/i915/display/intel_display.c | 83
> > > +++++++++++++++++++- drivers/gpu/drm/i915/display/intel_display.h |
> > > 2 + drivers/gpu/drm/i915/display/intel_sprite.c | 20 +++--
> > > 3 files changed, 97 insertions(+), 8 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/i915/display/intel_display.c
> > > b/drivers/gpu/drm/i915/display/intel_display.c
> > > index b5903ef3c5a0..6d5f59203258 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > > @@ -6237,6 +6237,73 @@ void skl_scaler_disable(const struct
> > intel_crtc_state *old_crtc_state)
> > > skl_detach_scaler(crtc, i);
> > > }
> > >
> > > +/**
> > > + * Theory behind setting nearest-neighbor integer scaling:
> > > + *
> > > + * 17 phase of 7 taps requires 119 coefficients in 60 dwords per set.
> > > + * The letter represents the filter tap (D is the center tap) and
> > > +the number
> > > + * represents the coefficient set for a phase (0-16).
> > > + *
> > > + * +------------+------------------------+------------------------+
> > > + * |Index value | Data value coeffient 1 | Data value coeffient 2 |
> > > + * +------------+------------------------+------------------------+
> > > + * | 00h | B0 | A0 |
> > > + * +------------+------------------------+------------------------+
> > > + * | 01h | D0 | C0 |
> > > + * +------------+------------------------+------------------------+
> > > + * | 02h | F0 | E0 |
> > > + * +------------+------------------------+------------------------+
> > > + * | 03h | A1 | G0 |
> > > + * +------------+------------------------+------------------------+
> > > + * | 04h | C1 | B1 |
> > > + * +------------+------------------------+------------------------+
> > > + * | ... | ... | ... |
> > > + * +------------+------------------------+------------------------+
> > > + * | 38h | B16 | A16 |
> > > + * +------------+------------------------+------------------------+
> > > + * | 39h | D16 | C16 |
> > > + * +------------+------------------------+------------------------+
> > > + * | 3Ah | F16 | C16 |
> > > + * +------------+------------------------+------------------------+
> > > + * | 3Bh | Reserved | G16 |
> > > + * +------------+------------------------+------------------------+
> > > + *
> > > + * To enable nearest-neighbor scaling: program scaler coefficents
> > > +with
> > > + * the center tap (Dxx) values set to 1 and all other values set to
> > > +0 as per
> > > + * SCALER_COEFFICIENT_FORMAT
> > > + *
> > > + */
> > > +void skl_setup_nearest_neighbor_filter(struct drm_i915_private
> > *dev_priv,
> > > + enum pipe pipe, int scaler_id)
> >
> > skl_scaler_...
> >
> > > +{
> > > +
> > > + int coeff = 0;
> > > + int phase = 0;
> > > + int tap;
> > > + int val = 0;
> >
> > Needlessly wide scope for most of these.
> >
> > > +
> > > + /*enable the index auto increment.*/
> > > + intel_de_write_fw(dev_priv, SKL_PS_COEF_INDEX_SET0(pipe,
> > scaler_id),
> > > + _PS_COEE_INDEX_AUTO_INC);
> > > +
> > > + for (phase = 0; phase < 17; phase++) {
> > > + for (tap = 0; tap < 7; tap++) {
> > > + coeff++;
> >
> > Can be part of the % check.
>
> OK.
>
> >
> > > + if (tap == 3)
> > > + val = (phase % 2) ? (0x800) : (0x800 << 16);
> >
> > Parens overload.
>
> OK. Will remove.
> >
> > > +
> > > + if (coeff % 2 == 0) {
> > > + intel_de_write_fw(dev_priv,
> > SKL_PS_COEF_DATA_SET0(pipe, scaler_id), val);
> > > + val = 0;
> >
> > Can drop this val=0 if you move the variable into tight scope and initialize
> > there.
>
> Moving val=0 initialization to the tight scope will not work here as we need
> to retain "val" and write only when 2 coefficients are ready (since 2
> coefficients are packed in 1 dword).
>
> e.g. for (12th , 11th) coefficients, coefficient reg value should be ( (0 << 16) | 0x800).
> If we initialize val = 0 in tight loop, 0 will be written to coefficient register.

Hmm, right. I guess I'd try to rearrange this to iterate the
registers directly instead of the phases and taps. Something
like this perhaps:

static int cnl_coef_tap(int i)
{
return i % 7;
}

static u16 cnl_coef(int t)
{
return t == 3 ? 0x0800 : 0x3000;
}

static void cnl_program_nearest_filter_coefs(void)
{
int i;

for (i = 0; i < 17 * 7; i += 2) {
uint32_t tmp;
int t;

t = cnl_coef_tap(i);
tmp = cnl_nearest_filter_coef(t);

t = cnl_coef_tap(i + 1);
tmp |= cnl_nearest_filter_coef(t) << 16;

intel_de_write_fw(tmp);
}
}

More readable I think. The downside being all those modulo operations
but hopefully that's all in the noise when it comes to performance.

--
Ville Syrj?l?
Intel

2020-03-12 14:06:23

by Ville Syrjälä

[permalink] [raw]

Subject: Re: [RFC][PATCH 0/5] Introduce drm scaling filter property

On Tue, Feb 25, 2020 at 12:35:40PM +0530, Pankaj Bharadiya wrote:
> Integer scaling (IS) is a nearest-neighbor upscaling technique that
> simply scales up the existing pixels by an integer (i.e., whole
> number) multiplier. Nearest-neighbor (NN) interpolation works by
> filling in the missing color values in the upscaled image with that of
> the coordinate-mapped nearest source pixel value.
>
> Both IS and NN preserve the clarity of the original image. In
> contrast, traditional upscaling algorithms, such as bilinear or
> bicubic interpolation, result in blurry upscaled images because they
> employ interpolation techniques that smooth out the transition from
> one pixel to another. Therefore, integer scaling is particularly
> useful for pixel art games that rely on sharp, blocky images to
> deliver their distinctive look.
>
> Many gaming communities have been asking for integer-mode scaling
> support, some links and background:
>
> https://software.intel.com/en-us/articles/integer-scaling-support-on-intel-graphics
> http://tanalin.com/en/articles/lossless-scaling/
> https://community.amd.com/thread/209107
> https://www.nvidia.com/en-us/geforce/forums/game-ready-drivers/13/1002/feature-request-nonblurry-upscaling-at-integer-rat/
>
> This patch series -
> - Introduces new scaling filter property to allow userspace to
> select the driver's default scaling filter or Nearest-neighbor(NN)
> filter for scaling operations on crtc/plane.
> - Implements and enable integer scaling for i915
>
> Userspace patch series link: TBD.

That needs to be done or this will go nowhere.

>
> Thanks to Shashank for initiating this work. His initial RFC can be
> found here [1]
>
> [1] https://patchwork.freedesktop.org/patch/337082/
>
> Modifications done in this series -
> - refactored code and incorporated initial review comments and
> added 2 scaling filter types (default and NN) to begin with.
> - added scaling filter property support for planes and new API
> helpers for drivers to setup this property.
> - rewrote code to enable integer scaling and NN filter for i915
>
>
> Pankaj Bharadiya (5):
> drm: Introduce scaling filter property
> drm/drm-kms.rst: Add Scaling filter property documentation
> drm/i915: Enable scaling filter for plane and pipe
> drm/i915: Introduce scaling filter related registers and bit fields.
> drm/i915/display: Add Nearest-neighbor based integer scaling support
>
> Documentation/gpu/drm-kms.rst | 6 ++
> drivers/gpu/drm/drm_atomic_uapi.c | 8 ++
> drivers/gpu/drm/drm_crtc.c | 16 +++
> drivers/gpu/drm/drm_mode_config.c | 13 +++
> drivers/gpu/drm/drm_plane.c | 35 +++++++
> drivers/gpu/drm/i915/display/intel_display.c | 100 ++++++++++++++++++-
> drivers/gpu/drm/i915/display/intel_display.h | 2 +
> drivers/gpu/drm/i915/display/intel_sprite.c | 32 ++++--
> drivers/gpu/drm/i915/i915_reg.h | 21 ++++
> include/drm/drm_crtc.h | 10 ++
> include/drm/drm_mode_config.h | 6 ++
> include/drm/drm_plane.h | 14 +++
> 12 files changed, 252 insertions(+), 11 deletions(-)
>
> --
> 2.23.0

--
Ville Syrj?l?
Intel

2020-03-12 15:38:13

by Laxminarayan Bharadiya, Pankaj

[permalink] [raw]

Subject: RE: [RFC][PATCH 0/5] Introduce drm scaling filter property

> -----Original Message-----
> From: Ville Syrj?l? <[email protected]>
> Sent: 12 March 2020 19:35
> To: Laxminarayan Bharadiya, Pankaj
> <[email protected]>
> Cc: [email protected]; [email protected]; intel-
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected];
> [email protected]; [email protected]; linux-
> [email protected]; Nautiyal, Ankit K <[email protected]>
> Subject: Re: [RFC][PATCH 0/5] Introduce drm scaling filter property
>
> On Tue, Feb 25, 2020 at 12:35:40PM +0530, Pankaj Bharadiya wrote:
> > Integer scaling (IS) is a nearest-neighbor upscaling technique that
> > simply scales up the existing pixels by an integer (i.e., whole
> > number) multiplier. Nearest-neighbor (NN) interpolation works by
> > filling in the missing color values in the upscaled image with that of
> > the coordinate-mapped nearest source pixel value.
> >
> > Both IS and NN preserve the clarity of the original image. In
> > contrast, traditional upscaling algorithms, such as bilinear or
> > bicubic interpolation, result in blurry upscaled images because they
> > employ interpolation techniques that smooth out the transition from
> > one pixel to another. Therefore, integer scaling is particularly
> > useful for pixel art games that rely on sharp, blocky images to
> > deliver their distinctive look.
> >
> > Many gaming communities have been asking for integer-mode scaling
> > support, some links and background:
> >
> > https://software.intel.com/en-us/articles/integer-scaling-support-on-i
> > ntel-graphics http://tanalin.com/en/articles/lossless-scaling/
> > https://community.amd.com/thread/209107
> > https://www.nvidia.com/en-us/geforce/forums/game-ready-drivers/13/1002
> > /feature-request-nonblurry-upscaling-at-integer-rat/
> >
> > This patch series -
> > - Introduces new scaling filter property to allow userspace to
> > select the driver's default scaling filter or Nearest-neighbor(NN)
> > filter for scaling operations on crtc/plane.
> > - Implements and enable integer scaling for i915
> >
> > Userspace patch series link: TBD.
>
> That needs to be done or this will go nowhere.

Yes, Sameer is working on enabling this feature in Kodi.
Sameer, please share link here once you post patches.

Thanks,
Pankaj

>
> >
> > Thanks to Shashank for initiating this work. His initial RFC can be
> > found here [1]
> >
> > [1] https://patchwork.freedesktop.org/patch/337082/
> >
> > Modifications done in this series -
> > - refactored code and incorporated initial review comments and
> > added 2 scaling filter types (default and NN) to begin with.
> > - added scaling filter property support for planes and new API
> > helpers for drivers to setup this property.
> > - rewrote code to enable integer scaling and NN filter for i915
> >
> >
> > Pankaj Bharadiya (5):
> > drm: Introduce scaling filter property
> > drm/drm-kms.rst: Add Scaling filter property documentation
> > drm/i915: Enable scaling filter for plane and pipe
> > drm/i915: Introduce scaling filter related registers and bit fields.
> > drm/i915/display: Add Nearest-neighbor based integer scaling support
> >
> > Documentation/gpu/drm-kms.rst | 6 ++
> > drivers/gpu/drm/drm_atomic_uapi.c | 8 ++
> > drivers/gpu/drm/drm_crtc.c | 16 +++
> > drivers/gpu/drm/drm_mode_config.c | 13 +++
> > drivers/gpu/drm/drm_plane.c | 35 +++++++
> > drivers/gpu/drm/i915/display/intel_display.c | 100 ++++++++++++++++++-
> > drivers/gpu/drm/i915/display/intel_display.h | 2 +
> > drivers/gpu/drm/i915/display/intel_sprite.c | 32 ++++--
> > drivers/gpu/drm/i915/i915_reg.h | 21 ++++
> > include/drm/drm_crtc.h | 10 ++
> > include/drm/drm_mode_config.h | 6 ++
> > include/drm/drm_plane.h | 14 +++
> > 12 files changed, 252 insertions(+), 11 deletions(-)
> >
> > --
> > 2.23.0
>
> --
> Ville Syrj?l?
> Intel

2020-03-12 16:02:25

by Ville Syrjälä

[permalink] [raw]

Subject: Re: [RFC][PATCH 0/5] Introduce drm scaling filter property

On Thu, Mar 12, 2020 at 03:37:03PM +0000, Laxminarayan Bharadiya, Pankaj wrote:
>
>
> > -----Original Message-----
> > From: Ville Syrj?l? <[email protected]>
> > Sent: 12 March 2020 19:35
> > To: Laxminarayan Bharadiya, Pankaj
> > <[email protected]>
> > Cc: [email protected]; [email protected]; intel-
> > [email protected]; [email protected]; [email protected];
> > [email protected]; [email protected];
> > [email protected]; [email protected]; linux-
> > [email protected]; Nautiyal, Ankit K <[email protected]>
> > Subject: Re: [RFC][PATCH 0/5] Introduce drm scaling filter property
> >
> > On Tue, Feb 25, 2020 at 12:35:40PM +0530, Pankaj Bharadiya wrote:
> > > Integer scaling (IS) is a nearest-neighbor upscaling technique that
> > > simply scales up the existing pixels by an integer (i.e., whole
> > > number) multiplier. Nearest-neighbor (NN) interpolation works by
> > > filling in the missing color values in the upscaled image with that of
> > > the coordinate-mapped nearest source pixel value.
> > >
> > > Both IS and NN preserve the clarity of the original image. In
> > > contrast, traditional upscaling algorithms, such as bilinear or
> > > bicubic interpolation, result in blurry upscaled images because they
> > > employ interpolation techniques that smooth out the transition from
> > > one pixel to another. Therefore, integer scaling is particularly
> > > useful for pixel art games that rely on sharp, blocky images to
> > > deliver their distinctive look.
> > >
> > > Many gaming communities have been asking for integer-mode scaling
> > > support, some links and background:
> > >
> > > https://software.intel.com/en-us/articles/integer-scaling-support-on-i
> > > ntel-graphics http://tanalin.com/en/articles/lossless-scaling/
> > > https://community.amd.com/thread/209107
> > > https://www.nvidia.com/en-us/geforce/forums/game-ready-drivers/13/1002
> > > /feature-request-nonblurry-upscaling-at-integer-rat/
> > >
> > > This patch series -
> > > - Introduces new scaling filter property to allow userspace to
> > > select the driver's default scaling filter or Nearest-neighbor(NN)
> > > filter for scaling operations on crtc/plane.
> > > - Implements and enable integer scaling for i915
> > >
> > > Userspace patch series link: TBD.
> >
> > That needs to be done or this will go nowhere.
>
> Yes, Sameer is working on enabling this feature in Kodi.
> Sameer, please share link here once you post patches.

And who is doing it for other stuff? I think this would be most useful
for games/emulators and such so IMO we should find a way to get it to
the hands of users doing those things.

--
Ville Syrj?l?
Intel

2020-03-13 08:46:33

by Laxminarayan Bharadiya, Pankaj

[permalink] [raw]

Subject: RE: [RFC][PATCH 5/5] drm/i915/display: Add Nearest-neighbor based integer scaling support

> -----Original Message-----
> From: Ville Syrj?l? <[email protected]>
> Sent: 12 March 2020 19:25
> To: Laxminarayan Bharadiya, Pankaj
> <[email protected]>
> Cc: [email protected]; [email protected]; intel-
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected];
> [email protected]; [email protected]; Joonas Lahtinen
> <[email protected]>; Vivi, Rodrigo <[email protected]>;
> Chris Wilson <[email protected]>; Souza, Jose <[email protected]>;
> De Marchi, Lucas <[email protected]>; Roper, Matthew D
> <[email protected]>; Deak, Imre <[email protected]>; Shankar,
> Uma <[email protected]>; [email protected]; Nautiyal, Ankit K
> <[email protected]>
> Subject: Re: [RFC][PATCH 5/5] drm/i915/display: Add Nearest-neighbor based
> integer scaling support
>
> On Thu, Mar 12, 2020 at 09:13:24AM +0000, Laxminarayan Bharadiya, Pankaj
> wrote:
> >
> >
> > > -----Original Message-----
> > > From: Ville Syrj?l? <[email protected]>
> > > Sent: 10 March 2020 21:47
> > > To: Laxminarayan Bharadiya, Pankaj
> > > <[email protected]>
> > > Cc: [email protected]; [email protected]; intel-
> > > [email protected]; [email protected];
> > > [email protected]; [email protected];
> > > [email protected]; [email protected]; [email protected];
> > > Joonas Lahtinen <[email protected]>; Vivi, Rodrigo
> > > <[email protected]>; Chris Wilson <[email protected]>;
> > > Souza, Jose <[email protected]>; De Marchi, Lucas
> > > <[email protected]>; Roper, Matthew D
> > > <[email protected]>; Deak, Imre <[email protected]>;
> > > Shankar, Uma <[email protected]>; linux- [email protected];
> > > Nautiyal, Ankit K <[email protected]>
> > > Subject: Re: [RFC][PATCH 5/5] drm/i915/display: Add Nearest-neighbor
> > > based integer scaling support
> > >
> > > On Tue, Feb 25, 2020 at 12:35:45PM +0530, Pankaj Bharadiya wrote:
> > > > Integer scaling (IS) is a nearest-neighbor upscaling technique
> > > > that simply scales up the existing pixels by an integer (i.e.,
> > > > whole
> > > > number) multiplier.Nearest-neighbor (NN) interpolation works by
> > > > filling in the missing color values in the upscaled image with
> > > > that of the coordinate-mapped nearest source pixel value.
> > > >
> > > > Both IS and NN preserve the clarity of the original image. Integer
> > > > scaling is particularly useful for pixel art games that rely on
> > > > sharp, blocky images to deliver their distinctive look.
> > > >
> > > > Program the scaler filter coefficients to enable the NN filter if
> > > > scaling filter property is set to
> > > > DRM_SCALING_FILTER_NEAREST_NEIGHBOR
> > > > and enable integer scaling.
> > > >
> > > > Bspec: 49247
> > > >
> > > > Signed-off-by: Pankaj Bharadiya
> > > > <[email protected]>
> > > > Signed-off-by: Ankit Nautiyal <[email protected]>
> > > > ---
> > > > drivers/gpu/drm/i915/display/intel_display.c | 83
> > > > +++++++++++++++++++- drivers/gpu/drm/i915/display/intel_display.h
> > > > +++++++++++++++++++|
> > > > 2 + drivers/gpu/drm/i915/display/intel_sprite.c | 20 +++--
> > > > 3 files changed, 97 insertions(+), 8 deletions(-)
> > > >
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_display.c
> > > > b/drivers/gpu/drm/i915/display/intel_display.c
> > > > index b5903ef3c5a0..6d5f59203258 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > > > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > > > @@ -6237,6 +6237,73 @@ void skl_scaler_disable(const struct
> > > intel_crtc_state *old_crtc_state)
> > > > skl_detach_scaler(crtc, i);
> > > > }
> > > >
> > > > +/**
> > > > + * Theory behind setting nearest-neighbor integer scaling:
> > > > + *
> > > > + * 17 phase of 7 taps requires 119 coefficients in 60 dwords per set.
> > > > + * The letter represents the filter tap (D is the center tap)
> > > > +and the number
> > > > + * represents the coefficient set for a phase (0-16).
> > > > + *
> > > > + * +------------+------------------------+------------------------+
> > > > + * |Index value | Data value coeffient 1 | Data value coeffient 2 |
> > > > + * +------------+------------------------+------------------------+
> > > > + * | 00h | B0 | A0 |
> > > > + * +------------+------------------------+------------------------+
> > > > + * | 01h | D0 | C0 |
> > > > + * +------------+------------------------+------------------------+
> > > > + * | 02h | F0 | E0 |
> > > > + * +------------+------------------------+------------------------+
> > > > + * | 03h | A1 | G0 |
> > > > + * +------------+------------------------+------------------------+
> > > > + * | 04h | C1 | B1 |
> > > > + * +------------+------------------------+------------------------+
> > > > + * | ... | ... | ... |
> > > > + * +------------+------------------------+------------------------+
> > > > + * | 38h | B16 | A16 |
> > > > + * +------------+------------------------+------------------------+
> > > > + * | 39h | D16 | C16 |
> > > > + * +------------+------------------------+------------------------+
> > > > + * | 3Ah | F16 | C16 |
> > > > + * +------------+------------------------+------------------------+
> > > > + * | 3Bh | Reserved | G16 |
> > > > + * +------------+------------------------+------------------------+
> > > > + *
> > > > + * To enable nearest-neighbor scaling: program scaler
> > > > +coefficents with
> > > > + * the center tap (Dxx) values set to 1 and all other values set
> > > > +to
> > > > +0 as per
> > > > + * SCALER_COEFFICIENT_FORMAT
> > > > + *
> > > > + */
> > > > +void skl_setup_nearest_neighbor_filter(struct drm_i915_private
> > > *dev_priv,
> > > > + enum pipe pipe, int scaler_id)
> > >
> > > skl_scaler_...
> > >
> > > > +{
> > > > +
> > > > + int coeff = 0;
> > > > + int phase = 0;
> > > > + int tap;
> > > > + int val = 0;
> > >
> > > Needlessly wide scope for most of these.
> > >
> > > > +
> > > > + /*enable the index auto increment.*/
> > > > + intel_de_write_fw(dev_priv, SKL_PS_COEF_INDEX_SET0(pipe,
> > > scaler_id),
> > > > + _PS_COEE_INDEX_AUTO_INC);
> > > > +
> > > > + for (phase = 0; phase < 17; phase++) {
> > > > + for (tap = 0; tap < 7; tap++) {
> > > > + coeff++;
> > >
> > > Can be part of the % check.
> >
> > OK.
> >
> > >
> > > > + if (tap == 3)
> > > > + val = (phase % 2) ? (0x800) : (0x800 << 16);
> > >
> > > Parens overload.
> >
> > OK. Will remove.
> > >
> > > > +
> > > > + if (coeff % 2 == 0) {
> > > > + intel_de_write_fw(dev_priv,
> > > SKL_PS_COEF_DATA_SET0(pipe, scaler_id), val);
> > > > + val = 0;
> > >
> > > Can drop this val=0 if you move the variable into tight scope and
> > > initialize there.
> >
> > Moving val=0 initialization to the tight scope will not work here as
> > we need to retain "val" and write only when 2 coefficients are ready
> > (since 2 coefficients are packed in 1 dword).
> >
> > e.g. for (12th , 11th) coefficients, coefficient reg value should be ( (0 << 16) |
> 0x800).
> > If we initialize val = 0 in tight loop, 0 will be written to coefficient register.
>
> Hmm, right. I guess I'd try to rearrange this to iterate the registers directly
> instead of the phases and taps. Something like this perhaps:
>
> static int cnl_coef_tap(int i)
> {
> return i % 7;
> }
>
> static u16 cnl_coef(int t)

cnl_coef -> cnl_nearest_filter_coef. Right?

> {
> return t == 3 ? 0x0800 : 0x3000;
> }
>
> static void cnl_program_nearest_filter_coefs(void)
> {
> int i;
>
> for (i = 0; i < 17 * 7; i += 2) {
> uint32_t tmp;
> int t;
>
> t = cnl_coef_tap(i);
> tmp = cnl_nearest_filter_coef(t);
>
> t = cnl_coef_tap(i + 1);
> tmp |= cnl_nearest_filter_coef(t) << 16;
>
> intel_de_write_fw(tmp);
> }
> }
>
> More readable I think. The downside being all those modulo operations but
> hopefully that's all in the noise when it comes to performance.

Looks better, thanks for spending time on this.
I will try this out.

Thanks,
Pankaj
>
> --
> Ville Syrj?l?
> Intel

2020-03-13 10:36:32

by Pekka Paalanen

[permalink] [raw]

Subject: Re: [RFC][PATCH 0/5] Introduce drm scaling filter property

On Thu, 12 Mar 2020 18:01:12 +0200
Ville Syrjälä <[email protected]> wrote:

> On Thu, Mar 12, 2020 at 03:37:03PM +0000, Laxminarayan Bharadiya, Pankaj wrote:
> >
> >
> > > -----Original Message-----
> > > From: Ville Syrjälä <[email protected]>
> > > Sent: 12 March 2020 19:35
> > > To: Laxminarayan Bharadiya, Pankaj
> > > <[email protected]>
> > > Cc: [email protected]; [email protected]; intel-
> > > [email protected]; [email protected]; [email protected];
> > > [email protected]; [email protected];
> > > [email protected]; [email protected]; linux-
> > > [email protected]; Nautiyal, Ankit K <[email protected]>
> > > Subject: Re: [RFC][PATCH 0/5] Introduce drm scaling filter property
> > >
> > > On Tue, Feb 25, 2020 at 12:35:40PM +0530, Pankaj Bharadiya wrote:
> > > > Integer scaling (IS) is a nearest-neighbor upscaling technique that
> > > > simply scales up the existing pixels by an integer (i.e., whole
> > > > number) multiplier. Nearest-neighbor (NN) interpolation works by
> > > > filling in the missing color values in the upscaled image with that of
> > > > the coordinate-mapped nearest source pixel value.
> > > >
> > > > Both IS and NN preserve the clarity of the original image. In
> > > > contrast, traditional upscaling algorithms, such as bilinear or
> > > > bicubic interpolation, result in blurry upscaled images because they
> > > > employ interpolation techniques that smooth out the transition from
> > > > one pixel to another. Therefore, integer scaling is particularly
> > > > useful for pixel art games that rely on sharp, blocky images to
> > > > deliver their distinctive look.
> > > >
> > > > Many gaming communities have been asking for integer-mode scaling
> > > > support, some links and background:
> > > >
> > > > https://software.intel.com/en-us/articles/integer-scaling-support-on-i
> > > > ntel-graphics http://tanalin.com/en/articles/lossless-scaling/
> > > > https://community.amd.com/thread/209107
> > > > https://www.nvidia.com/en-us/geforce/forums/game-ready-drivers/13/1002
> > > > /feature-request-nonblurry-upscaling-at-integer-rat/
> > > >
> > > > This patch series -
> > > > - Introduces new scaling filter property to allow userspace to
> > > > select the driver's default scaling filter or Nearest-neighbor(NN)
> > > > filter for scaling operations on crtc/plane.
> > > > - Implements and enable integer scaling for i915
> > > >
> > > > Userspace patch series link: TBD.
> > >
> > > That needs to be done or this will go nowhere.
> >
> > Yes, Sameer is working on enabling this feature in Kodi.
> > Sameer, please share link here once you post patches.
>
> And who is doing it for other stuff? I think this would be most useful
> for games/emulators and such so IMO we should find a way to get it to
> the hands of users doing those things.
>

Hi,

FWIW, being able to tell KMS to use nearest-neighbor filtering could be
useful for
https://gitlab.freedesktop.org/wayland/weston/-/merge_requests/394
as a follow-up.

Thanks,
pq

Attachments:

(No filename) (849.00 B)
OpenPGP digital signature

2020-03-13 19:55:06

by Ville Syrjälä

[permalink] [raw]

Subject: Re: [RFC][PATCH 5/5] drm/i915/display: Add Nearest-neighbor based integer scaling support

On Fri, Mar 13, 2020 at 08:45:35AM +0000, Laxminarayan Bharadiya, Pankaj wrote:
>
>
> > -----Original Message-----
> > From: Ville Syrj?l? <[email protected]>
> > Sent: 12 March 2020 19:25
> > To: Laxminarayan Bharadiya, Pankaj
> > <[email protected]>
> > Cc: [email protected]; [email protected]; intel-
> > [email protected]; [email protected]; [email protected];
> > [email protected]; [email protected];
> > [email protected]; [email protected]; Joonas Lahtinen
> > <[email protected]>; Vivi, Rodrigo <[email protected]>;
> > Chris Wilson <[email protected]>; Souza, Jose <[email protected]>;
> > De Marchi, Lucas <[email protected]>; Roper, Matthew D
> > <[email protected]>; Deak, Imre <[email protected]>; Shankar,
> > Uma <[email protected]>; [email protected]; Nautiyal, Ankit K
> > <[email protected]>
> > Subject: Re: [RFC][PATCH 5/5] drm/i915/display: Add Nearest-neighbor based
> > integer scaling support
> >
> > On Thu, Mar 12, 2020 at 09:13:24AM +0000, Laxminarayan Bharadiya, Pankaj
> > wrote:
> > >
> > >
> > > > -----Original Message-----
> > > > From: Ville Syrj?l? <[email protected]>
> > > > Sent: 10 March 2020 21:47
> > > > To: Laxminarayan Bharadiya, Pankaj
> > > > <[email protected]>
> > > > Cc: [email protected]; [email protected]; intel-
> > > > [email protected]; [email protected];
> > > > [email protected]; [email protected];
> > > > [email protected]; [email protected]; [email protected];
> > > > Joonas Lahtinen <[email protected]>; Vivi, Rodrigo
> > > > <[email protected]>; Chris Wilson <[email protected]>;
> > > > Souza, Jose <[email protected]>; De Marchi, Lucas
> > > > <[email protected]>; Roper, Matthew D
> > > > <[email protected]>; Deak, Imre <[email protected]>;
> > > > Shankar, Uma <[email protected]>; linux- [email protected];
> > > > Nautiyal, Ankit K <[email protected]>
> > > > Subject: Re: [RFC][PATCH 5/5] drm/i915/display: Add Nearest-neighbor
> > > > based integer scaling support
> > > >
> > > > On Tue, Feb 25, 2020 at 12:35:45PM +0530, Pankaj Bharadiya wrote:
> > > > > Integer scaling (IS) is a nearest-neighbor upscaling technique
> > > > > that simply scales up the existing pixels by an integer (i.e.,
> > > > > whole
> > > > > number) multiplier.Nearest-neighbor (NN) interpolation works by
> > > > > filling in the missing color values in the upscaled image with
> > > > > that of the coordinate-mapped nearest source pixel value.
> > > > >
> > > > > Both IS and NN preserve the clarity of the original image. Integer
> > > > > scaling is particularly useful for pixel art games that rely on
> > > > > sharp, blocky images to deliver their distinctive look.
> > > > >
> > > > > Program the scaler filter coefficients to enable the NN filter if
> > > > > scaling filter property is set to
> > > > > DRM_SCALING_FILTER_NEAREST_NEIGHBOR
> > > > > and enable integer scaling.
> > > > >
> > > > > Bspec: 49247
> > > > >
> > > > > Signed-off-by: Pankaj Bharadiya
> > > > > <[email protected]>
> > > > > Signed-off-by: Ankit Nautiyal <[email protected]>
> > > > > ---
> > > > > drivers/gpu/drm/i915/display/intel_display.c | 83
> > > > > +++++++++++++++++++- drivers/gpu/drm/i915/display/intel_display.h
> > > > > +++++++++++++++++++|
> > > > > 2 + drivers/gpu/drm/i915/display/intel_sprite.c | 20 +++--
> > > > > 3 files changed, 97 insertions(+), 8 deletions(-)
> > > > >
> > > > > diff --git a/drivers/gpu/drm/i915/display/intel_display.c
> > > > > b/drivers/gpu/drm/i915/display/intel_display.c
> > > > > index b5903ef3c5a0..6d5f59203258 100644
> > > > > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > > > > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > > > > @@ -6237,6 +6237,73 @@ void skl_scaler_disable(const struct
> > > > intel_crtc_state *old_crtc_state)
> > > > > skl_detach_scaler(crtc, i);
> > > > > }
> > > > >
> > > > > +/**
> > > > > + * Theory behind setting nearest-neighbor integer scaling:
> > > > > + *
> > > > > + * 17 phase of 7 taps requires 119 coefficients in 60 dwords per set.
> > > > > + * The letter represents the filter tap (D is the center tap)
> > > > > +and the number
> > > > > + * represents the coefficient set for a phase (0-16).
> > > > > + *
> > > > > + * +------------+------------------------+------------------------+
> > > > > + * |Index value | Data value coeffient 1 | Data value coeffient 2 |
> > > > > + * +------------+------------------------+------------------------+
> > > > > + * | 00h | B0 | A0 |
> > > > > + * +------------+------------------------+------------------------+
> > > > > + * | 01h | D0 | C0 |
> > > > > + * +------------+------------------------+------------------------+
> > > > > + * | 02h | F0 | E0 |
> > > > > + * +------------+------------------------+------------------------+
> > > > > + * | 03h | A1 | G0 |
> > > > > + * +------------+------------------------+------------------------+
> > > > > + * | 04h | C1 | B1 |
> > > > > + * +------------+------------------------+------------------------+
> > > > > + * | ... | ... | ... |
> > > > > + * +------------+------------------------+------------------------+
> > > > > + * | 38h | B16 | A16 |
> > > > > + * +------------+------------------------+------------------------+
> > > > > + * | 39h | D16 | C16 |
> > > > > + * +------------+------------------------+------------------------+
> > > > > + * | 3Ah | F16 | C16 |
> > > > > + * +------------+------------------------+------------------------+
> > > > > + * | 3Bh | Reserved | G16 |
> > > > > + * +------------+------------------------+------------------------+
> > > > > + *
> > > > > + * To enable nearest-neighbor scaling: program scaler
> > > > > +coefficents with
> > > > > + * the center tap (Dxx) values set to 1 and all other values set
> > > > > +to
> > > > > +0 as per
> > > > > + * SCALER_COEFFICIENT_FORMAT
> > > > > + *
> > > > > + */
> > > > > +void skl_setup_nearest_neighbor_filter(struct drm_i915_private
> > > > *dev_priv,
> > > > > + enum pipe pipe, int scaler_id)
> > > >
> > > > skl_scaler_...
> > > >
> > > > > +{
> > > > > +
> > > > > + int coeff = 0;
> > > > > + int phase = 0;
> > > > > + int tap;
> > > > > + int val = 0;
> > > >
> > > > Needlessly wide scope for most of these.
> > > >
> > > > > +
> > > > > + /*enable the index auto increment.*/
> > > > > + intel_de_write_fw(dev_priv, SKL_PS_COEF_INDEX_SET0(pipe,
> > > > scaler_id),
> > > > > + _PS_COEE_INDEX_AUTO_INC);
> > > > > +
> > > > > + for (phase = 0; phase < 17; phase++) {
> > > > > + for (tap = 0; tap < 7; tap++) {
> > > > > + coeff++;
> > > >
> > > > Can be part of the % check.
> > >
> > > OK.
> > >
> > > >
> > > > > + if (tap == 3)
> > > > > + val = (phase % 2) ? (0x800) : (0x800 << 16);
> > > >
> > > > Parens overload.
> > >
> > > OK. Will remove.
> > > >
> > > > > +
> > > > > + if (coeff % 2 == 0) {
> > > > > + intel_de_write_fw(dev_priv,
> > > > SKL_PS_COEF_DATA_SET0(pipe, scaler_id), val);
> > > > > + val = 0;
> > > >
> > > > Can drop this val=0 if you move the variable into tight scope and
> > > > initialize there.
> > >
> > > Moving val=0 initialization to the tight scope will not work here as
> > > we need to retain "val" and write only when 2 coefficients are ready
> > > (since 2 coefficients are packed in 1 dword).
> > >
> > > e.g. for (12th , 11th) coefficients, coefficient reg value should be ( (0 << 16) |
> > 0x800).
> > > If we initialize val = 0 in tight loop, 0 will be written to coefficient register.
> >
> > Hmm, right. I guess I'd try to rearrange this to iterate the registers directly
> > instead of the phases and taps. Something like this perhaps:
> >
> > static int cnl_coef_tap(int i)
> > {
> > return i % 7;
> > }
> >
> > static u16 cnl_coef(int t)
>
> cnl_coef -> cnl_nearest_filter_coef. Right?

Right.

>
> > {
> > return t == 3 ? 0x0800 : 0x3000;
> > }
> >
> > static void cnl_program_nearest_filter_coefs(void)
> > {
> > int i;
> >
> > for (i = 0; i < 17 * 7; i += 2) {
> > uint32_t tmp;
> > int t;
> >
> > t = cnl_coef_tap(i);
> > tmp = cnl_nearest_filter_coef(t);
> >
> > t = cnl_coef_tap(i + 1);
> > tmp |= cnl_nearest_filter_coef(t) << 16;
> >
> > intel_de_write_fw(tmp);
> > }
> > }
> >
> > More readable I think. The downside being all those modulo operations but
> > hopefully that's all in the noise when it comes to performance.
>
> Looks better, thanks for spending time on this.
> I will try this out.
>
> Thanks,
> Pankaj
> >
> > --
> > Ville Syrj?l?
> > Intel

--
Ville Syrj?l?
Intel