Re: [Intel-gfx] [PATCH v2] drm/i915: Support Async Flip on Linear buffers

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Wed, Jun 01, 2022 at 09:54:11AM +0530, Arun R Murthy wrote:
> Starting from Gen12 Async Flip is supported on linear buffers.

I was asking for justification for the gen12+ approach. Why not
expose it on earlier platforms?

> This patch enables support for async on linear buffer.
> 
> UseCase: In Hybrid graphics, for harware unsupported pixel formats it
> will be converted to linear memory and then composed.
> 
> v2: Added use case
> 
> Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index e71b69425309..da2df7239353 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -7524,6 +7524,13 @@ static int intel_async_flip_check_hw(struct intel_atomic_state *state, struct in
>  		 * this selectively if required.
>  		 */
>  		switch (new_plane_state->hw.fb->modifier) {
> +		case DRM_FORMAT_MOD_LINEAR:
> +			if (DISPLAY_VER(i915) < 12) {
> +				drm_dbg_kms(&i915->drm,
> +					"[PLANE:%d:%s] Modifier does not support async flips\n",
> +					plane->base.base.id, plane->base.name);
> +				return -EINVAL;
> +			}
>  		case I915_FORMAT_MOD_X_TILED:
>  		case I915_FORMAT_MOD_Y_TILED:
>  		case I915_FORMAT_MOD_Yf_TILED:
> -- 
> 2.25.1

-- 
Ville Syrjälä
Intel