Re: [PATCH v13 0/6] Add Synopsys DesignWare HDMI RX Controller

[Hans Verkuil]

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.

Regards,

	Hans