2024-05-02 10:40:36

by Shawn Sung

Subject: [PATCH v7 09/18] drm/mediatek: Support constant blending in OVL

From: Hsiao Chien Sung <[email protected]>

Support constant alpha blending in OVL.

Signed-off-by: Hsiao Chien Sung <[email protected]>
---
drivers/gpu/drm/mediatek/mtk_disp_ovl.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
index 738244a6164e8..e41fd83e36e79 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
@@ -38,6 +38,7 @@
#define DISP_REG_OVL_PITCH_MSB(n) (0x0040 + 0x20 * (n))
#define OVL_PITCH_MSB_2ND_SUBBUF BIT(16)
#define DISP_REG_OVL_PITCH(n) (0x0044 + 0x20 * (n))
+#define OVL_CONST_BLEND BIT(28)
#define DISP_REG_OVL_RDMA_CTRL(n) (0x00c0 + 0x20 * (n))
#define DISP_REG_OVL_RDMA_GMC(n) (0x00c8 + 0x20 * (n))
#define DISP_REG_OVL_ADDR_MT2701 0x0040
@@ -428,6 +429,7 @@ void mtk_ovl_layer_config(struct device *dev, unsigned int idx,
unsigned int fmt = pending->format;
unsigned int offset = (pending->y << 16) | pending->x;
unsigned int src_size = (pending->height << 16) | pending->width;
+ unsigned int ignore_pixel_alpha = 0;
unsigned int con;
bool is_afbc = pending->modifier != DRM_FORMAT_MOD_LINEAR;
union overlay_pitch {
@@ -449,6 +451,9 @@ void mtk_ovl_layer_config(struct device *dev, unsigned int idx,
if (state->base.fb && state->base.fb->format->has_alpha)
con |= OVL_CON_AEN | OVL_CON_ALPHA;

+ if (state->base.fb && !state->base.fb->format->has_alpha)
+ ignore_pixel_alpha = OVL_CONST_BLEND;
+
if (pending->rotation & DRM_MODE_REFLECT_Y) {
con |= OVL_CON_VIRT_FLIP;
addr += (pending->height - 1) * pending->pitch;
@@ -464,8 +469,8 @@ void mtk_ovl_layer_config(struct device *dev, unsigned int idx,

mtk_ddp_write_relaxed(cmdq_pkt, con, &ovl->cmdq_reg, ovl->regs,
DISP_REG_OVL_CON(idx));
- mtk_ddp_write_relaxed(cmdq_pkt, overlay_pitch.split_pitch.lsb, &ovl->cmdq_reg, ovl->regs,
- DISP_REG_OVL_PITCH(idx));
+ mtk_ddp_write_relaxed(cmdq_pkt, overlay_pitch.split_pitch.lsb | ignore_pixel_alpha,
+ &ovl->cmdq_reg, ovl->regs, DISP_REG_OVL_PITCH(idx));
mtk_ddp_write_relaxed(cmdq_pkt, src_size, &ovl->cmdq_reg, ovl->regs,
DISP_REG_OVL_SRC_SIZE(idx));
mtk_ddp_write_relaxed(cmdq_pkt, offset, &ovl->cmdq_reg, ovl->regs,
--
2.18.0

2024-05-03 05:29:47

by CK Hu (胡俊光)

Subject: Re: [PATCH v7 09/18] drm/mediatek: Support constant blending in OVL

Hi, Shawn:

On Thu, 2024-05-02 at 18:38 +0800, Shawn Sung wrote:
> From: Hsiao Chien Sung <[email protected]>
>
> Support constant alpha blending in OVL.

What is constant alpha? I search in wikipedia but find nothing about
constant alpha. This is not a common term, so explain it.

Regards,
CK

>
> Signed-off-by: Hsiao Chien Sung <[email protected]>
> ---
> drivers/gpu/drm/mediatek/mtk_disp_ovl.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> index 738244a6164e8..e41fd83e36e79 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> @@ -38,6 +38,7 @@
> #define DISP_REG_OVL_PITCH_MSB(n) (0x0040 + 0x20 * (n))
> #define OVL_PITCH_MSB_2ND_SUBBUF BIT(16)
> #define DISP_REG_OVL_PITCH(n) (0x0044 + 0x20
> * (n))
> +#define OVL_CONST_BLEND BIT(28)
> #define DISP_REG_OVL_RDMA_CTRL(n) (0x00c0 + 0x20 * (n))
> #define DISP_REG_OVL_RDMA_GMC(n) (0x00c8 + 0x20 * (n))
> #define DISP_REG_OVL_ADDR_MT2701 0x0040
> @@ -428,6 +429,7 @@ void mtk_ovl_layer_config(struct device *dev,
> unsigned int idx,
> unsigned int fmt = pending->format;
> unsigned int offset = (pending->y << 16) | pending->x;
> unsigned int src_size = (pending->height << 16) | pending-
> >width;
> + unsigned int ignore_pixel_alpha = 0;
> unsigned int con;
> bool is_afbc = pending->modifier != DRM_FORMAT_MOD_LINEAR;
> union overlay_pitch {
> @@ -449,6 +451,9 @@ void mtk_ovl_layer_config(struct device *dev,
> unsigned int idx,
> if (state->base.fb && state->base.fb->format->has_alpha)
> con |= OVL_CON_AEN | OVL_CON_ALPHA;
>
> + if (state->base.fb && !state->base.fb->format->has_alpha)
> + ignore_pixel_alpha = OVL_CONST_BLEND;
> +
> if (pending->rotation & DRM_MODE_REFLECT_Y) {
> con |= OVL_CON_VIRT_FLIP;
> addr += (pending->height - 1) * pending->pitch;
> @@ -464,8 +469,8 @@ void mtk_ovl_layer_config(struct device *dev,
> unsigned int idx,
>
> mtk_ddp_write_relaxed(cmdq_pkt, con, &ovl->cmdq_reg, ovl->regs,
> DISP_REG_OVL_CON(idx));
> - mtk_ddp_write_relaxed(cmdq_pkt, overlay_pitch.split_pitch.lsb,
> &ovl->cmdq_reg, ovl->regs,
> - DISP_REG_OVL_PITCH(idx));
> + mtk_ddp_write_relaxed(cmdq_pkt, overlay_pitch.split_pitch.lsb |
> ignore_pixel_alpha,
> + &ovl->cmdq_reg, ovl->regs,
> DISP_REG_OVL_PITCH(idx));
> mtk_ddp_write_relaxed(cmdq_pkt, src_size, &ovl->cmdq_reg, ovl-
> >regs,
> DISP_REG_OVL_SRC_SIZE(idx));
> mtk_ddp_write_relaxed(cmdq_pkt, offset, &ovl->cmdq_reg, ovl-
> >regs,

2024-05-03 05:58:48

by CK Hu (胡俊光)

Subject: Re: [PATCH v7 09/18] drm/mediatek: Support constant blending in OVL

Hi, Shawn:

On Thu, 2024-05-02 at 18:38 +0800, Shawn Sung wrote:
> From: Hsiao Chien Sung <[email protected]>
>
> Support constant alpha blending in OVL.
>
> Signed-off-by: Hsiao Chien Sung <[email protected]>
> ---
> drivers/gpu/drm/mediatek/mtk_disp_ovl.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> index 738244a6164e8..e41fd83e36e79 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> @@ -38,6 +38,7 @@
> #define DISP_REG_OVL_PITCH_MSB(n) (0x0040 + 0x20 * (n))
> #define OVL_PITCH_MSB_2ND_SUBBUF BIT(16)
> #define DISP_REG_OVL_PITCH(n) (0x0044 + 0x20
> * (n))
> +#define OVL_CONST_BLEND BIT(28)
> #define DISP_REG_OVL_RDMA_CTRL(n) (0x00c0 + 0x20 * (n))
> #define DISP_REG_OVL_RDMA_GMC(n) (0x00c8 + 0x20 * (n))
> #define DISP_REG_OVL_ADDR_MT2701 0x0040
> @@ -428,6 +429,7 @@ void mtk_ovl_layer_config(struct device *dev,
> unsigned int idx,
> unsigned int fmt = pending->format;
> unsigned int offset = (pending->y << 16) | pending->x;
> unsigned int src_size = (pending->height << 16) | pending-
> >width;
> + unsigned int ignore_pixel_alpha = 0;
> unsigned int con;
> bool is_afbc = pending->modifier != DRM_FORMAT_MOD_LINEAR;
> union overlay_pitch {
> @@ -449,6 +451,9 @@ void mtk_ovl_layer_config(struct device *dev,
> unsigned int idx,
> if (state->base.fb && state->base.fb->format->has_alpha)
> con |= OVL_CON_AEN | OVL_CON_ALPHA;
>
> + if (state->base.fb && !state->base.fb->format->has_alpha)
> + ignore_pixel_alpha = OVL_CONST_BLEND;
> +
> if (pending->rotation & DRM_MODE_REFLECT_Y) {
> con |= OVL_CON_VIRT_FLIP;
> addr += (pending->height - 1) * pending->pitch;
> @@ -464,8 +469,8 @@ void mtk_ovl_layer_config(struct device *dev,
> unsigned int idx,
>
> mtk_ddp_write_relaxed(cmdq_pkt, con, &ovl->cmdq_reg, ovl->regs,
> DISP_REG_OVL_CON(idx));
> - mtk_ddp_write_relaxed(cmdq_pkt, overlay_pitch.split_pitch.lsb,
> &ovl->cmdq_reg, ovl->regs,
> - DISP_REG_OVL_PITCH(idx));
> + mtk_ddp_write_relaxed(cmdq_pkt, overlay_pitch.split_pitch.lsb |
> ignore_pixel_alpha,
> + &ovl->cmdq_reg, ovl->regs,

In original code, RGB888 or other pixel format without alpha works
correctly. Why need to set this? If this is a bug fix, add Fixes tag.

Regards,
CK

> DISP_REG_OVL_PITCH(idx));
> mtk_ddp_write_relaxed(cmdq_pkt, src_size, &ovl->cmdq_reg, ovl-
> >regs,
> DISP_REG_OVL_SRC_SIZE(idx));
> mtk_ddp_write_relaxed(cmdq_pkt, offset, &ovl->cmdq_reg, ovl-
> >regs,