diff options
Diffstat (limited to 'drivers/gpu/drm/drm_plane.c')
| -rw-r--r-- | drivers/gpu/drm/drm_plane.c | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c index 0dd43882fe7c..b373958ecb30 100644 --- a/drivers/gpu/drm/drm_plane.c +++ b/drivers/gpu/drm/drm_plane.c @@ -128,6 +128,13 @@ * pairs supported by this plane. The blob is a struct * drm_format_modifier_blob. Without this property the plane doesn't * support buffers with modifiers. Userspace cannot change this property. + * + * Note that userspace can check the &DRM_CAP_ADDFB2_MODIFIERS driver + * capability for general modifier support. If this flag is set then every + * plane will have the IN_FORMATS property, even when it only supports + * DRM_FORMAT_MOD_LINEAR. Before linux kernel release v5.1 there have been + * various bugs in this area with inconsistencies between the capability + * flag and per-plane properties. */ static unsigned int drm_num_planes(struct drm_device *dev) @@ -277,8 +284,14 @@ static int __drm_universal_plane_init(struct drm_device *dev, format_modifier_count++; } - if (format_modifier_count) + /* autoset the cap and check for consistency across all planes */ + if (format_modifier_count) { + drm_WARN_ON(dev, !config->allow_fb_modifiers && + !list_empty(&config->plane_list)); config->allow_fb_modifiers = true; + } else { + drm_WARN_ON(dev, config->allow_fb_modifiers); + } plane->modifier_count = format_modifier_count; plane->modifiers = kmalloc_array(format_modifier_count, @@ -360,6 +373,9 @@ static int __drm_universal_plane_init(struct drm_device *dev, * drm_universal_plane_init() to let the DRM managed resource infrastructure * take care of cleanup and deallocation. * + * Drivers supporting modifiers must set @format_modifiers on all their planes, + * even those that only support DRM_FORMAT_MOD_LINEAR. + * * Returns: * Zero on success, error code on failure. */ |