From b67f408a0c2427d5d7c682cfbdad87c4ff73265b Mon Sep 17 00:00:00 2001 From: Qinyun Tan Date: Tue, 1 Sep 2026 16:32:32 +0800 Subject: drm/qxl: create blend mode property on primary and cursor planes 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. Both the qxl primary and cursor planes expose ARGB8888 and trip this on driver load. qxl submits cursors as SPICE_CURSOR_TYPE_ALPHA, which the SPICE protocol explicitly defines as a "pre-multiplied ARGB8888 pixmap" (Spice Protocol, "Cursor channel definition" section [1]). This matches the blend mode userspace has always assumed when the property is not attached. Expose a "pixel blend mode" property advertising only DRM_MODE_BLEND_PREMULTI to make these semantics explicit and silence the warning. The primary plane is the bottom-most plane so its blend mode has no visible effect; advertise the same value there for consistency. No functional change. [1] https://www.spice-space.org/spice-protocol.html Fixes: 860e748bddcc ("drm: ensure blend mode supported if pixel format with alpha exposed") Reviewed-by: Thomas Zimmermann Signed-off-by: Qinyun Tan Signed-off-by: Thomas Zimmermann Link: https://patch.msgid.link/20260901083234.1828755-3-qinyuntan@linux.alibaba.com --- drivers/gpu/drm/qxl/qxl_display.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/qxl/qxl_display.c b/drivers/gpu/drm/qxl/qxl_display.c index 2fc41fb90aaa..0719fc6a52d5 100644 --- a/drivers/gpu/drm/qxl/qxl_display.c +++ b/drivers/gpu/drm/qxl/qxl_display.c @@ -30,6 +30,7 @@ #include #include #include +#include #include #include #include @@ -993,6 +994,9 @@ static struct drm_plane *qxl_create_plane(struct qxl_device *qdev, drm_plane_helper_add(plane, helper_funcs); + drm_plane_create_blend_mode_property(plane, + BIT(DRM_MODE_BLEND_PREMULTI)); + return plane; free_plane: -- cgit v1.2.3