[Intel-gfx] [PATCH] drm/i915: Support FP16 compressed formats on MTL

[Ville Syrjälä]

On Thu, Oct 12, 2023 at 11:56:20AM +0530, Melanie Lobo wrote:
> MTL supports FP16 format which is a binary floating-point computer
> number format that occupies 16 bits in computer memory.Platform shall
> render compression in display engine to receive FP16 compressed formats.
> 
> This kernel change was tested with IGT patch,
> https://patchwork.freedesktop.org/patch/562014/
> 
> Test-with: 20231011095520.10768-1-melanie.lobo at intel.com
> 
> Signed-off-by: Melanie Lobo <melanie.lobo at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_fb.c            | 2 ++
>  drivers/gpu/drm/i915/display/skl_universal_plane.c | 4 +---
>  2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_fb.c b/drivers/gpu/drm/i915/display/intel_fb.c
> index e7678571b0d7..868cfc75e687 100644
> --- a/drivers/gpu/drm/i915/display/intel_fb.c
> +++ b/drivers/gpu/drm/i915/display/intel_fb.c
> @@ -91,6 +91,8 @@ static const struct drm_format_info gen12_ccs_formats[] = {
>  	{ .format = DRM_FORMAT_P016, .num_planes = 4,
>  	  .char_per_block = { 2, 4, 1, 1 }, .block_w = { 1, 1, 2, 2 }, .block_h = { 1, 1, 1, 1 },
>  	  .hsub = 2, .vsub = 2, .is_yuv = true },
> +	{ .format = DRM_FORMAT_XRGB16161616F, .depth = 64, .num_planes = 2,
> +	  .char_per_block = { 4, 1}, .block_w = { 1, 2}, .block_h = { 1, 1}, .hsub = 1, .vsub = 1 },

That chars_per_block=4 doesn't look sensible for a 64bit format.
And I suspect the block_w=2 for the CCS is also wrong.

>  };
>  
>  /*
> diff --git a/drivers/gpu/drm/i915/display/skl_universal_plane.c b/drivers/gpu/drm/i915/display/skl_universal_plane.c
> index 245a64332cc7..6ec5b96904c3 100644
> --- a/drivers/gpu/drm/i915/display/skl_universal_plane.c
> +++ b/drivers/gpu/drm/i915/display/skl_universal_plane.c
> @@ -2122,9 +2122,7 @@ static bool gen12_plane_format_mod_supported(struct drm_plane *_plane,
>  	case DRM_FORMAT_Y216:
>  	case DRM_FORMAT_XVYU12_16161616:
>  	case DRM_FORMAT_XVYU16161616:
> -		if (!intel_fb_is_ccs_modifier(modifier))
> -			return true;
> -		fallthrough;
> +		return true;
>  	default:
>  		return false;
>  	}
> -- 
> 2.17.1

-- 
Ville Syrjälä
Intel