Re: [PATCH 1/8] display: fix blend_mode for non-overlay planes

[Bert Karwatzki <spasswolf@web.de>]

Am Freitag, dem 21.08.2026 um 14:31 -0600 schrieb Alex Hung:
> This looks like a fix for the same problem Melissa tried to address in
> 
> https://lore.kernel.org/amd-gfx/DS0PR12MB65342AEDED0D035DFA92E4189CA32@DS0PR12MB6534.namprd12.prod.outlook.com/T/#mf6847a9e8d013adae40afa3c2ca0c64ebd3fcb50
> 
> Please advise if it is for a different issue.
> 
> Thanks.
> 
> On 8/21/26 13:42, Bert Karwatzki wrote:
> > Am Freitag, dem 21.08.2026 um 14:47 -0400 schrieb Joshua Peisach:
> > > On Fri Aug 14, 2026 at 11:17 AM EDT, Bert Karwatzki wrote:
> > > > Previously drm_plane_create_blend_mode_property() was only called for
> > > > planes of type DRM_PLANE_TYPE_OVERLAY. Since commit commit 860e748bddcc
> > > > ("drm: ensure blend mode supported if pixel format with alpha exposed")
> > > > this results in warnings from validate_blend_mode_for_alpha_formats().
> > > > We fix this here by calling drm_plane_create_blend_mode_property() for
> > > > all plane types if the plane is supporting a format with
> > > > per_pixel_alpha.
> > > > 
> > > > Signed-off-by: Bert Karwatzki <spasswolf@web.de>
> > > > ---
> > > >   drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c  | 5 ++++-
> > > >   drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c | 3 +--
> > > >   2 files changed, 5 insertions(+), 3 deletions(-)
> > > > 
> > > > diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c
> > > > index 62eac6e65334..a6a54351ea56 100644
> > > > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c
> > > > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c
> > > > @@ -755,13 +755,16 @@ int amdgpu_dm_crtc_init(struct amdgpu_display_manager *dm,
> > > >   	struct drm_plane *cursor_plane;
> > > >   	bool has_degamma;
> > > >   	int res = -ENOMEM;
> > > > +	struct dc_plane_cap dummy_cap = {
> > > > +		.per_pixel_alpha = 1,
> > > > +	};
> > > >   
> > > >   	cursor_plane = kzalloc_obj(*cursor_plane);
> > > >   	if (!cursor_plane)
> > > >   		goto fail;
> > > >   
> > > >   	cursor_plane->type = DRM_PLANE_TYPE_CURSOR;
> > > > -	res = amdgpu_dm_plane_init(dm, cursor_plane, 0, NULL);
> > > > +	res = amdgpu_dm_plane_init(dm, cursor_plane, 0, &dummy_cap);
> > > >   
> > > >   	acrtc = kzalloc_obj(struct amdgpu_crtc);
> > > >   	if (!acrtc)
> > > > diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
> > > > index 824ef3ce5de0..4c0c6a8a0dac 100644
> > > > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
> > > > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
> > > > @@ -2208,8 +2208,7 @@ int amdgpu_dm_plane_init(struct amdgpu_display_manager *dm,
> > > >   	if (res)
> > > >   		return res;
> > > >   
> > > > -	if (plane->type == DRM_PLANE_TYPE_OVERLAY &&
> > > > -	    plane_cap && plane_cap->per_pixel_alpha) {
> > > > +	if (plane_cap && plane_cap->per_pixel_alpha) {
> > > >   		unsigned int blend_caps = BIT(DRM_MODE_BLEND_PIXEL_NONE) |
> > > >   					  BIT(DRM_MODE_BLEND_PREMULTI) |
> > > >   					  BIT(DRM_MODE_BLEND_COVERAGE);
> > > 
> > > Not sure where the full patch set is, but this does make the warning
> > > go away.
> > > 
> > > Tested-by: Joshua Peisach <jpeisach@ubuntu.com>
> > 
> > This is actually the only patch, the 1/8 is an artifact from using
> > git format-patch which I forgot to remove.
> > 
> > Bert Karwatzki

Patch 2 of this series

https://lore.kernel.org/amd-gfx/DS0PR12MB65342AEDED0D035DFA92E4189CA32@DS0PR12MB6534.namprd12.prod.outlook.com/T/#mf6847a9e8d013adae40afa3c2ca0c64ebd3fcb50

is fixing the same issue, I think.

Bert Karwatzki