Re: [PATCH 2/9] drm/i915: Allow async flips with compression on ICL

["Hogander, Jouni" <jouni.hogander@intel.com>]

On Wed, 2024-10-09 at 21:22 +0300, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> 
> Apparently ICL can do async flips with CCS. In fact it already
> seems to work on GLK, but apparently can lead to underruns there
> so we'll only enable it for ICL.
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

Reviewed-by: Jouni Högander <jouni.hogander@intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_display.c | 21
> +++++++++++++++++++-
>  1 file changed, 20 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c
> b/drivers/gpu/drm/i915/display/intel_display.c
> index 21d412b158e8..70a5e5357a14 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -6507,7 +6507,26 @@ static int intel_async_flip_check_hw(struct
> intel_atomic_state *state, struct in
>                                 return -EINVAL;
>                         }
>                         break;
> -
> +               case I915_FORMAT_MOD_Y_TILED_CCS:
> +               case I915_FORMAT_MOD_Yf_TILED_CCS:
> +                       /*
> +                        * Display WA #0731: skl
> +                        * WaDisableRCWithAsyncFlip: skl
> +                        * "When render decompression is enabled,
> hardware
> +                        *  internally converts the Async flips to
> Sync flips."
> +                        *
> +                        * Display WA #1159: glk
> +                        * "Async flip with render compression may
> result in
> +                        *  intermittent underrun corruption."
> +                        */
> +                       if (DISPLAY_VER(i915) < 11) {
> +                               drm_dbg_kms(&i915->drm,
> +                                           "[PLANE:%d:%s] Modifier
> 0x%llx does not support async flip on display ver %d\n",
> +                                           plane->base.base.id,
> plane->base.name,
> +                                           new_plane_state->hw.fb-
> >modifier, DISPLAY_VER(i915));
> +                               return -EINVAL;
> +                       }
> +                       break;
>                 case I915_FORMAT_MOD_X_TILED:
>                 case I915_FORMAT_MOD_Y_TILED:
>                 case I915_FORMAT_MOD_Yf_TILED: