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| author | Qinyun Tan <qinyuntan@linux.alibaba.com> | 2026-09-01 16:32:31 +0800 |
|---|---|---|
| committer | Thomas Zimmermann <tzimmermann@suse.de> | 2026-09-08 15:12:26 +0200 |
| commit | 313f798f52a5e46b0e419d05f977d40aaeac4106 (patch) | |
| tree | c83624bb21e520b5470c87e7fb6ea6772ca13011 | |
| parent | 28cc4d5a75bb07d0eb2fa178db355b04483f5aca (diff) | |
| download | linux-313f798f52a5e46b0e419d05f977d40aaeac4106.tar.gz linux-313f798f52a5e46b0e419d05f977d40aaeac4106.zip | |
drm/ast: create blend mode property on cursor plane
Since commit 860e748bddcc ("drm: ensure blend mode supported if pixel
format with alpha exposed"), drm_mode_config_validate() warns when a
plane exposes an alpha pixel format but not the "pixel blend mode"
property. The ast cursor plane (ARGB4444, ARGB8888) trips this on
driver load:
[PLANE:37:plane-1] pixel format with alpha exposed but blend mode not setup
WARNING: drivers/gpu/drm/drm_mode_config.c:872 at drm_mode_config_validate+0x48f/0x510 [drm]
...
Call Trace:
drm_dev_register+0x1ce/0x290 [drm]
ast_pci_probe+0x19d/0x3f0 [ast]
local_pci_probe+0x41/0x90
Per Thomas Zimmermann's review, the ASPEED documentation describes the
hardware cursor as blending with straight (non-pre-multiplied) alpha,
which corresponds to DRM_MODE_BLEND_COVERAGE. Expose a "pixel blend
mode" property advertising only DRM_MODE_BLEND_COVERAGE to make the
hardware semantics explicit and silence the warning.
Fixes: 860e748bddcc ("drm: ensure blend mode supported if pixel format with alpha exposed")
Suggested-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Qinyun Tan <qinyuntan@linux.alibaba.com>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patch.msgid.link/20260901083234.1828755-2-qinyuntan@linux.alibaba.com
| -rw-r--r-- | drivers/gpu/drm/ast/ast_cursor.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/gpu/drm/ast/ast_cursor.c b/drivers/gpu/drm/ast/ast_cursor.c index fd19c45f2abe..690d4cd1db5e 100644 --- a/drivers/gpu/drm/ast/ast_cursor.c +++ b/drivers/gpu/drm/ast/ast_cursor.c @@ -25,6 +25,7 @@ #include <linux/sizes.h> #include <drm/drm_atomic.h> +#include <drm/drm_blend.h> #include <drm/drm_damage_helper.h> #include <drm/drm_format_helper.h> #include <drm/drm_gem_atomic_helper.h> @@ -355,6 +356,8 @@ int ast_cursor_plane_init(struct ast_device *ast) } drm_plane_helper_add(cursor_plane, &ast_cursor_plane_helper_funcs); drm_plane_enable_fb_damage_clips(cursor_plane); + drm_plane_create_blend_mode_property(cursor_plane, + BIT(DRM_MODE_BLEND_COVERAGE)); return 0; } |