mið., 10. jan. 2024 kl. 13:09 skrifaði Werner Sembach <wse@xxxxxxxxxxxxxxxxxxx>: > > Hi, > > Am 10.01.24 um 11:11 schrieb Andri Yngvason: > > Hi, > > > > mið., 10. jan. 2024 kl. 09:27 skrifaði Maxime Ripard <mripard@xxxxxxxxxx>: > >> On Tue, Jan 09, 2024 at 06:11:02PM +0000, Andri Yngvason wrote: > >>> From: Werner Sembach <wse@xxxxxxxxxxxxxxxxxxx> > >>> > >>> Add a new general drm property "preferred color format" which can be used > >>> by userspace to tell the graphic drivers to which color format to use. > >>> > >>> Possible options are: > >>> - auto (default/current behaviour) > >>> - rgb > >>> - ycbcr444 > >>> - ycbcr422 (not supported by both amdgpu and i915) > >>> - ycbcr420 > >>> > >>> In theory the auto option should choose the best available option for the > >>> current setup, but because of bad internal conversion some monitors look > >>> better with rgb and some with ycbcr444. > >> I looked at the patch and I couldn't find what is supposed to happen if > >> you set it to something else than auto, and the driver can't match that. > >> Are we supposed to fallback to the "auto" behaviour, or are we suppose > >> to reject the mode entirely? > >> > >> The combination with the active output format property suggests the > >> former, but we should document it explicitly. > > It is also my understanding that it should fall back to the "auto" > > behaviour. I will add this to the documentation. > > Yes, that was the intention, and then userspace can check, but it wasn't well > received: https://gitlab.freedesktop.org/drm/amd/-/issues/476#note_964530 > > Actually a lot of the thoughts that went into the original patch set can be > found in that topic. > > There was another iteration of the patch set that I never finished and sent to > the LKML because I got discouraged by this: > https://lore.kernel.org/dri-devel/20210623102923.70877c1a@eldfell/ Well, I've implemented this for sway and wlroots now and Simon has reacted positively, so this does appear likely to end up as a feature in wlroots based compositors. > > I can try to dig it up, but it is completely untested and I don't think I still > have the respective TODO list anymore, so I don't know if it is a better or > worst starting point than the last iteration I sent to the LKML. > You can send the patches to me if you want and I can see if they're useful. I'm really only interested in the color format part though. Alternatively, you can continue your work and post it to LKML and I can focus on the userspace side and testing. By the way, I have an HDMI analyzer that can tell me the actual color format. Thanks, Andri
