2018-04-10 18:29:32

by Ayan Halder

Subject: [PATCH] drm/arm/malidp: Preserve LAYER_FORMAT contents when setting format

On some Mali-DP processors, the LAYER_FORMAT register contains fields
other than the format. These bits were unconditionally cleared when
setting the pixel format, whereas they should be preserved at their
reset values.

Reported-by: Brian Starkey <[email protected]>
Reported-by: Liviu Dudau <[email protected]>
Signed-off-by: Ayan Kumar halder <[email protected]>
---
drivers/gpu/drm/arm/malidp_planes.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/arm/malidp_planes.c b/drivers/gpu/drm/arm/malidp_planes.c
index 7a44897..4af3c1f 100644
--- a/drivers/gpu/drm/arm/malidp_planes.c
+++ b/drivers/gpu/drm/arm/malidp_planes.c
@@ -23,6 +23,7 @@

/* Layer specific register offsets */
#define MALIDP_LAYER_FORMAT 0x000
+#define LAYER_FORMAT_MASK 0x3f
#define MALIDP_LAYER_CONTROL 0x004
#define LAYER_ENABLE (1 << 0)
#define LAYER_FLOWCFG_MASK 7
@@ -337,7 +338,9 @@ static void malidp_de_plane_update(struct drm_plane *plane,
dest_w = plane->state->crtc_w;
dest_h = plane->state->crtc_h;

- malidp_hw_write(mp->hwdev, ms->format, mp->layer->base);
+ val = malidp_hw_read(mp->hwdev, mp->layer->base);
+ val = (val & ~LAYER_FORMAT_MASK) | ms->format;
+ malidp_hw_write(mp->hwdev, val, mp->layer->base);

for (i = 0; i < ms->n_planes; i++) {
/* calculate the offset for the layer's plane registers */
--
2.7.4

2018-04-12 10:21:26

by Liviu Dudau

Subject: Re: [PATCH] drm/arm/malidp: Preserve LAYER_FORMAT contents when setting format

On Tue, Apr 10, 2018 at 07:25:03PM +0100, Ayan Kumar Halder wrote:
> On some Mali-DP processors, the LAYER_FORMAT register contains fields
> other than the format. These bits were unconditionally cleared when
> setting the pixel format, whereas they should be preserved at their
> reset values.
>
> Reported-by: Brian Starkey <[email protected]>
> Reported-by: Liviu Dudau <[email protected]>
> Signed-off-by: Ayan Kumar halder <[email protected]>

Acked-by: Liviu Dudau <[email protected]>

Thanks for catching this in testing!

Best regards,
Liviu

> ---
> drivers/gpu/drm/arm/malidp_planes.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/arm/malidp_planes.c b/drivers/gpu/drm/arm/malidp_planes.c
> index 7a44897..4af3c1f 100644
> --- a/drivers/gpu/drm/arm/malidp_planes.c
> +++ b/drivers/gpu/drm/arm/malidp_planes.c
> @@ -23,6 +23,7 @@
>
> /* Layer specific register offsets */
> #define MALIDP_LAYER_FORMAT 0x000
> +#define LAYER_FORMAT_MASK 0x3f
> #define MALIDP_LAYER_CONTROL 0x004
> #define LAYER_ENABLE (1 << 0)
> #define LAYER_FLOWCFG_MASK 7
> @@ -337,7 +338,9 @@ static void malidp_de_plane_update(struct drm_plane *plane,
> dest_w = plane->state->crtc_w;
> dest_h = plane->state->crtc_h;
>
> - malidp_hw_write(mp->hwdev, ms->format, mp->layer->base);
> + val = malidp_hw_read(mp->hwdev, mp->layer->base);
> + val = (val & ~LAYER_FORMAT_MASK) | ms->format;
> + malidp_hw_write(mp->hwdev, val, mp->layer->base);
>
> for (i = 0; i < ms->n_planes; i++) {
> /* calculate the offset for the layer's plane registers */
> --
> 2.7.4
>

--
====================
| I would like to |
| fix the world, |
| but they're not |
| giving me the |
\ source code! /
---------------
¯\_(ツ)_/¯