Re: [Intel-gfx] [PATCH 1/9] drm/i915: Reject planar formats when doing async flips
On Mon, Oct 18, 2021 at 02:50:22PM +0300, Ville Syrjala wrote:
> From: Ville Syrjälä
>
> Async flips are only capable of changing PLANE_SURF, hence we
> they can't easily be used with planar formats.
>
> Older platforms could require updating AUX_DIST as well, which
> is not possible. We'd have to make sure AUX_DIST doesn't change
> before allowing the async flip through. If we could get async
> flips with CCS then that might be interesting, but since the hw
> doesn't allow async flips with CCS I don't see much point in
> allowing this for planar formats either. No one renders their
> game content in YUV anyway.
>
> icl+ could in theory do this I suppose since each color plane
> has its own PLANE_SURF register, but I don't know if there is
> some magic to guarantee that both the Y and UV plane would
> async flip synchronously if you will. Ie. beyond just a clean
> tear we'd potentially get some kind of weird tear with some
> random mix of luma and chroma from the old and new frames.
>
> So let's just say no to async flips when scanning out planar
> formats.
>
> Cc: Karthik B S
> Signed-off-by: Ville Syrjälä
Reviewed-by: Stanislav Lisovskiy
> ---
> drivers/gpu/drm/i915/display/intel_display.c | 6 ++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c
> b/drivers/gpu/drm/i915/display/intel_display.c
> index ce5d6633029a..8bb87e839f4a 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -8884,6 +8884,12 @@ static int intel_atomic_check_async(struct
> intel_atomic_state *state)
> return -EINVAL;
> }
>
> + if (new_plane_state->hw.fb->format->num_planes > 1) {
> + drm_dbg_kms(&i915->drm,
> + "Planar formats not supported with async
> flips\n");
> + return -EINVAL;
> + }
> +
> if (old_plane_state->view.color_plane[0].stride !=
> new_plane_state->view.color_plane[0].stride) {
> drm_dbg_kms(&i915->drm, "Stride cannot be changed in
> async flip\n");
> --
> 2.32.0
>
[Intel-gfx] [PATCH 1/9] drm/i915: Reject planar formats when doing async flips
From: Ville Syrjälä
Async flips are only capable of changing PLANE_SURF, hence we
they can't easily be used with planar formats.
Older platforms could require updating AUX_DIST as well, which
is not possible. We'd have to make sure AUX_DIST doesn't change
before allowing the async flip through. If we could get async
flips with CCS then that might be interesting, but since the hw
doesn't allow async flips with CCS I don't see much point in
allowing this for planar formats either. No one renders their
game content in YUV anyway.
icl+ could in theory do this I suppose since each color plane
has its own PLANE_SURF register, but I don't know if there is
some magic to guarantee that both the Y and UV plane would
async flip synchronously if you will. Ie. beyond just a clean
tear we'd potentially get some kind of weird tear with some
random mix of luma and chroma from the old and new frames.
So let's just say no to async flips when scanning out planar
formats.
Cc: Karthik B S
Signed-off-by: Ville Syrjälä
---
drivers/gpu/drm/i915/display/intel_display.c | 6 ++
1 file changed, 6 insertions(+)
diff --git a/drivers/gpu/drm/i915/display/intel_display.c
b/drivers/gpu/drm/i915/display/intel_display.c
index ce5d6633029a..8bb87e839f4a 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -8884,6 +8884,12 @@ static int intel_atomic_check_async(struct
intel_atomic_state *state)
return -EINVAL;
}
+ if (new_plane_state->hw.fb->format->num_planes > 1) {
+ drm_dbg_kms(&i915->drm,
+ "Planar formats not supported with async
flips\n");
+ return -EINVAL;
+ }
+
if (old_plane_state->view.color_plane[0].stride !=
new_plane_state->view.color_plane[0].stride) {
drm_dbg_kms(&i915->drm, "Stride cannot be changed in
async flip\n");
--
2.32.0
