[Intel-gfx] [PATCH] drm/i915: Fix per-pixel alpha with CCS

[Heinrich Fink]

On Mon, 3 Jun 2019 at 16:25, Ville Syrjala
<ville.syrjala at linux.intel.com> wrote:
>
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>
> We forgot to set .has_alpha=true for the A+CCS formats when the code
> started to consult .has_alpha. This manifests as A+CCS being treated
> as X+CCS which means no per-pixel alpha blending. Fix the format
> list appropriately.
>
> Cc: stable at vger.kernel.org
> Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Cc: Matt Roper <matthew.d.roper at intel.com>
> Cc: Heinrich Fink <heinrich.fink at daqri.com>
> Reported-by: Heinrich Fink <heinrich.fink at daqri.com>
> Fixes: b20815255693 ("drm/i915: Add plane alpha blending support, v2.")
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_display.c | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index c3e2b1178d55..67d796f4747e 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -2463,10 +2463,14 @@ static unsigned int intel_fb_modifier_to_tiling(u64 fb_modifier)
>   * main surface.
>   */
>  static const struct drm_format_info ccs_formats[] = {
> -       { .format = DRM_FORMAT_XRGB8888, .depth = 24, .num_planes = 2, .cpp = { 4, 1, }, .hsub = 8, .vsub = 16, },
> -       { .format = DRM_FORMAT_XBGR8888, .depth = 24, .num_planes = 2, .cpp = { 4, 1, }, .hsub = 8, .vsub = 16, },
> -       { .format = DRM_FORMAT_ARGB8888, .depth = 32, .num_planes = 2, .cpp = { 4, 1, }, .hsub = 8, .vsub = 16, },
> -       { .format = DRM_FORMAT_ABGR8888, .depth = 32, .num_planes = 2, .cpp = { 4, 1, }, .hsub = 8, .vsub = 16, },
> +       { .format = DRM_FORMAT_XRGB8888, .depth = 24, .num_planes = 2,
> +         .cpp = { 4, 1, }, .hsub = 8, .vsub = 16, },
> +       { .format = DRM_FORMAT_XBGR8888, .depth = 24, .num_planes = 2,
> +         .cpp = { 4, 1, }, .hsub = 8, .vsub = 16, },
> +       { .format = DRM_FORMAT_ARGB8888, .depth = 32, .num_planes = 2,
> +         .cpp = { 4, 1, }, .hsub = 8, .vsub = 16, .has_alpha = true, },
> +       { .format = DRM_FORMAT_ABGR8888, .depth = 32, .num_planes = 2,
> +         .cpp = { 4, 1, }, .hsub = 8, .vsub = 16, .has_alpha = true, },
>  };
>
>  static const struct drm_format_info *
> --
> 2.21.0
>

Just tested it on our image, fixes the bug and works for me. Thank you
for the swift fix!