drm/gem-fb-helper: Use actual bpp for size calculations

The AFBC helpers derive the number of bits per pixel from the deprecated
drm_format_info.cpp[] field, which does not take into account block
sizes.

Fix this by using the actual number of bits per pixel instead.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/b1d938d903157627c4ac101df92a1f3bf8ebe83d.1657294931.git.geert@linux-m68k.org

diff --git a/drivers/gpu/drm/drm_gem_framebuffer_helper.c b/drivers/gpu/drm/drm_gem_framebuffer_helper.c
index 61339a9..880a497 100644 (file)
--- a/drivers/gpu/drm/drm_gem_framebuffer_helper.c
+++ b/drivers/gpu/drm/drm_gem_framebuffer_helper.c
@@ -490,6 +490,8 @@ void drm_gem_fb_end_cpu_access(struct drm_framebuffer *fb, enum dma_data_directi
 }
 EXPORT_SYMBOL(drm_gem_fb_end_cpu_access);
 
+// TODO Drop this function and replace by drm_format_info_bpp() once all
+// DRM_FORMAT_* provide proper block info in drivers/gpu/drm/drm_fourcc.c
 static __u32 drm_gem_afbc_get_bpp(struct drm_device *dev,
                                  const struct drm_mode_fb_cmd2 *mode_cmd)
 {
@@ -497,11 +499,6 @@ static __u32 drm_gem_afbc_get_bpp(struct drm_device *dev,
 
        info = drm_get_format_info(dev, mode_cmd);
 
-       /* use whatever a driver has set */
-       if (info->cpp[0])
-               return info->cpp[0] * 8;
-
-       /* guess otherwise */
        switch (info->format) {
        case DRM_FORMAT_YUV420_8BIT:
                return 12;
@@ -510,11 +507,8 @@ static __u32 drm_gem_afbc_get_bpp(struct drm_device *dev,
        case DRM_FORMAT_VUY101010:
                return 30;
        default:
-               break;
+               return drm_format_info_bpp(info, 0);
        }
-
-       /* all attempts failed */
-       return 0;
 }
 
 static int drm_gem_afbc_min_size(struct drm_device *dev,