On 3/5/25 12:03, Dmitry Osipenko wrote: > On 3/5/25 11:10, Hans Verkuil wrote: >> On 05/03/2025 01:59, Tim Surber wrote: >>> Hi Dmitry, >>> >>> I did some more testing. That the Apple TV did not work was a bit >>> misleading. >>> >>> It was just, that the Apple TV defaulted to 4:4:4 Chroma which does not >>> work at all for me. (The same happens using the vendor driver). >>> >>> When I changed the EDID to match the vendor driver the HDMI handshake >>> happened with 4:2:0 chroma, where I could verify even 4k60fps using your >>> driver, nice! >>> >>> So the remaining problems I see are: >>> - 4:4:4 chroma not working in any resolution >>> - 4:2:2 and RGB not working in 4k60fps (is this a hardware limitation?) >>> >>> A possible workaround could be to disable these non supported formats in >>> the default EDID. >> I would like to merge this driver this week, since otherwise it will likely >> slip to v6.16. So if there is a working EDID, perhaps it can be used for now, >> and later on it can be patched if there is a better EDID. >> >> Would this EDID work? Tim, can you try this? >> >> v4l2-ctl --set-edid type=hdmi-4k-600mhz,ycbcr444,ycbcr422 >> >> Alternatively, if there is indeed a HW limitation that prevents 4kp60 to work, >> try this: >> >> v4l2-ctl --set-edid type=hdmi-4k-300mhz,ycbcr444,ycbcr422 >> >> Whichever of the two works is what we can use as default EDID. > > Disabling 444 and 422 is an option. Though, they work on my setup at > 4k@60p. > > In general, it often a challenge to get 4k@60p properly with any of > these small board devices. 4k@60p works only using a short HDMI cable > for me. Also, not everyone aware that the micro HDMI adapter needs to be > compliant with HDMI 2.0 for 4k@60, that's why 300MHz is the default. > > Will be nice to have the good EDID enabled by default in the defconfig. > Dealing with problems like that will be a headache for majority of > people, IMO. BTW, I don't see it as a blocker. Driver works in general, new issues can be resolved with additional patches. -- Best regards, Dmitry
