Hi Am 25.08.26 um 12:54 schrieb Roshan Kumar:
Commit 860e748bddcc ("drm: ensure blend mode supported if pixel format with alpha exposed") added validation that warns when a plane exposes an alpha format without a pixel blend mode property. PL111 exposes several such formats but does not attach the property.The PL110/PL111 controller scans out a single framebuffer and does not blend its alpha channel with a background. Advertise DRM_MODE_BLEND_PIXEL_NONE to match the existing hardware behavior.
Why does the driver report ARGB formats in the first place. I'm looking at the code at [1] and I don't see any difference to XRGB. Unless I'm missing something, please remove ARGB formats from this driver instead. Drivers should not report formats they don't support.
[1] https://elixir.bootlin.com/linux/v7.2.2/source/drivers/gpu/drm/pl111/pl111_display.c#L259
Best regards Thomas
With panic_on_warn enabled, this warning prevents the syzkaller vexpress-a15 manager from booting. The change was tested on current master with QEMU 10 and the existing production DTB; the guest reached sshd and returned an SSH banner. Fixes: 860e748bddcc ("drm: ensure blend mode supported if pixel format with alpha exposed") Link: https://github.com/google/syzkaller/issues/7805 Signed-off-by: Roshan Kumar <[email protected]> --- drivers/gpu/drm/pl111/pl111_display.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/pl111/pl111_display.c b/drivers/gpu/drm/pl111/pl111_display.c index 5d10bc5..758b297 100644 --- a/drivers/gpu/drm/pl111/pl111_display.c +++ b/drivers/gpu/drm/pl111/pl111_display.c @@ -15,6 +15,7 @@ #include <linux/media-bus-format.h> #include <linux/of_graph.h>+#include <drm/drm_blend.h>#include <drm/drm_fb_dma_helper.h> #include <drm/drm_fourcc.h> #include <drm/drm_framebuffer.h> @@ -596,5 +597,10 @@ int pl111_display_init(struct drm_device *drm) if (ret) return ret;+ ret = drm_plane_create_blend_mode_property(&priv->pipe.plane,+ BIT(DRM_MODE_BLEND_PIXEL_NONE)); + if (ret) + return ret; + return 0; }
-- -- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com GF: Jochen Jaser, Andrew McDonald, (HRB 36809, AG Nürnberg)
