target/linux/bcm27xx/patches-6.1/950-1285-vc4-hvs-Fix-lbm-size-calculation-for-yuv-6012.patch

   1 From c0169f2c197d005aff8acfbc618de6e7f6b1ab94 Mon Sep 17 00:00:00 2001
   2 From: Florian Wesch <fw@dividuum.de>
   3 Date: Tue, 5 Mar 2024 15:17:56 +0100
   4 Subject: [PATCH 1285/1295] vc4/hvs: Fix lbm size calculation for yuv (#6012)
   5
   6 The code was reducing the number of components by one when we were not
   7 blending with alpha. But that only makes sense if the components include
   8 alpha.
   9
  10 For YUV, we were reducing the number of components for Y from one to zero
  11 which resulted in no lbm space being allocated.
  12
  13 Fixes: https://github.com/raspberrypi/linux/issues/5912
  14
  15 Signed-off-by: Dom Cobley <popcornmix@gmail.com>
  16 Co-authored-by: Dom Cobley <popcornmix@gmail.com>
  17 ---
  18  drivers/gpu/drm/vc4/vc4_plane.c | 2 +-
  19  1 file changed, 1 insertion(+), 1 deletion(-)
  20
  21 --- a/drivers/gpu/drm/vc4/vc4_plane.c
  22 +++ b/drivers/gpu/drm/vc4/vc4_plane.c
  23 @@ -733,7 +733,7 @@ static unsigned int vc4_lbm_channel_size
  24         if (!components)
  25                 return 0;
  26
  27 -       if (state->alpha != DRM_BLEND_ALPHA_OPAQUE)
  28 +       if (state->alpha != DRM_BLEND_ALPHA_OPAQUE && info->has_alpha)
  29                 components -= 1;
  30
  31         words = width * wpc * components;