On Wed, Sep 02, 2026 at 08:58:37PM +0200, Melissa Wen wrote: > > > On 01/09/2026 09:12, Thorsten Leemhuis wrote: > > On 8/28/26 14:19, Viktor Jägersküpper wrote: > > > On 8/28/26 09:22, Thorsten Leemhuis wrote: > > > > On 8/27/26 19:14, Melissa Wen wrote: > > > > > On 27/08/2026 18:37, Melissa Wen wrote: > > > > > > On 27/08/2026 15:34, Alex Deucher wrote: > > > > > > > On Wed, Aug 26, 2026 at 7:20 AM Melissa Wen <[email protected]> > > > > > > > wrote: > > > > > > > > PREMULTI was the default DRM blend mode until 9813e158d13d > > > > > > > > ("drm/drm_blend: allow blend mode property without PREMULTI") > > > > > > > > introduced > > > > > > > > the possibility of exposing the blend mode property without > > > > > > > > PREMULTI > > > > > > > > being supported. However, > > > > > > > > __drm_atomic_helper_plane_state_init() still > > > > > > > > resets pixel_blend_mode to PREMULTI (hardcoded), ignoring the > > > > > > > > supported > > > > > > > > mode in this property. In the same series, 860e748bddcc ("drm: > > > > > > > > ensure > > > > > > > > blend mode supported if pixel format with alpha exposed") starts > > > > > > > > warning > > > > > > > > drivers that supports alpha formats in a given planes but > > > > > > > > doesn't > > > > > > > > support blend mode property, which includes AMD primary and > > > > > > > > cursor > > > > > > > > planes. > > > > > [...] > > > > > > > I presume you are planning to apply this directly to drm-misc for > > > > > > > 7.3? > > > > > > Right, I'll apply to drm-misc-fixes, just doing it now. > > > > > Or not now. I have to wait for -rc1. > > > > > I'll keep it on my radar. > > > > Hmmm, that sounds like these fixes will miss -rc1. But wouldn't it be > > > > good to get them included there, as they afaik (please correct me if I'm > > > > wrong, is easy to mix something up from the outside!) the warnings that > > > > Greg described as ""It's not good to boot and have a bunch of warnings > > > > already happening, resulting in a "tainted" kernel before I have the > > > > chance to break anything manually myself...""[1], as more people then > > > > will likely encounter this (and then waste time on bisecting an issue > > > > known for weeks for which a fix exists). > > > > > > > > [1] > > > > https://lore.kernel.org/all/2026082651-spinning-cornbread-33ba@gregkh/ > > > If I understand correctly, the *actual* fix (for all affected drivers) > > > will make it into 7.3-rc1, see this answer to my question: > > > https://lore.kernel.org/dri-devel/20260826-brave-nyala-of-elevation-d23aea@houat/ > > > > > > This fix is queued in drm-next: > > > https://gitlab.freedesktop.org/drm/kernel/-/commit/271e90eb5f9ff34951647e5ed33c1775eebcca50 > > Ahh, yeah, many thx, I had see this downgrade to drm_warn() (which made > > it to -rc1, yeah \o/), but had not made the right connections. :-/ > > > > FWIW, even with that done there is now one amdgpu regression report > > about this already post-rc1: > > https://lore.kernel.org/all/CANkdJ2VvJQSBzyOq=LgSW1=z8-yin_r9py2ij0ujdo55+db...@mail.gmail.com/ > > > > """ > > [...] After updating from kernel v7.2.2 to v7.3-rc1, several DRM plane > > warnings regarding unset blend modes for pixel formats with alpha > > channels started appearing in dmesg during initialization. > > > > [drm] [PLANE:44:plane-0] pixel format with alpha exposed but blend > > mode not setup. Please fix. [...] > > """ > > > > Will reply there now. Wondering if we need to do something about that if > > more reports like that show up, but let's wait if that's the case. > > I just applied this series to drm-misc-fixes: > - c3080b58d81d ("drm/atomic-state-helper: set pixel_blend_mode to prop > default on reset") > - f0c75da0a6b4 ("drm/amd/display: fix missing blend-mode-prop warning for > DCN") > - 332ad707e38f ("drm/amd/display: advertise PIXEL_NONE and PREMULTI blend > mode for DCE") > > With this, the dmesg message will no longer appear on the AMD driver.
Great, thanks!
