Re: [Intel-gfx] [PATCH v2 14/17] uapi/drm/dg2: Format modifier for DG2 unified compression and clear color

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

On Thu, Oct 21, 2021 at 07:56:24PM +0530, Ramalingam C wrote:
> From: Matt Roper <matthew.d.roper@intel.com>
> 
> DG2 unifies render compression and media compression into a single
> format for the first time.  The programming and buffer layout is
> supposed to match compression on older gen12 platforms, but the
> actual compression algorithm is different from any previous platform; as
> such, we need a new framebuffer modifier to represent buffers in this
> format, but otherwise we can re-use the existing gen12 compression driver
> logic.
> 
> DG2 clear color render compression uses Tile4 layout. Therefore, we need
> to define a new format modifier for uAPI to support clear color rendering.
> 
> Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
> Signed-off-by: Mika Kahola <mika.kahola@intel.com> (v2)
> Signed-off-by: Juha-Pekka Heikkilä <juha-pekka.heikkila@intel.com>
> Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
> cc: Simon Ser <contact@emersion.fr>
> Cc: Pekka Paalanen <ppaalanen@gmail.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c  |  3 ++
>  .../drm/i915/display/intel_display_types.h    | 10 +++-
>  drivers/gpu/drm/i915/display/intel_fb.c       |  7 +++
>  .../drm/i915/display/skl_universal_plane.c    | 49 +++++++++++++++++--
>  include/uapi/drm/drm_fourcc.h                 | 30 ++++++++++++
>  5 files changed, 94 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 9b678839bf2b..2949fe9f5b9f 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -1013,6 +1013,9 @@ intel_get_format_info(const struct drm_mode_fb_cmd2 *cmd)
>  					  cmd->pixel_format);
>  	case I915_FORMAT_MOD_Y_TILED_GEN12_RC_CCS:
>  	case I915_FORMAT_MOD_Y_TILED_GEN12_MC_CCS:
> +	case I915_FORMAT_MOD_F_TILED_DG2_RC_CCS:
> +	case I915_FORMAT_MOD_F_TILED_DG2_MC_CCS:
> +	case I915_FORMAT_MOD_F_TILED_DG2_RC_CCS_CC:
>  		return lookup_format_info(gen12_ccs_formats,
>  					  ARRAY_SIZE(gen12_ccs_formats),
>  					  cmd->pixel_format);

That seems not right. Flat CCS is invisible to the user so the format
info should not include a CCS plane.

-- 
Ville Syrjälä
Intel