On Wed, 25 May 2022 06:04:44 +0000 Simon Ser contact@emersion.fr wrote:
On Wednesday, May 25th, 2022 at 00:03, Alex Deucher alexdeucher@gmail.com wrote:
Why would anyone want to run at 8bpc when they have a panel with higher color depth? So I think someone is going to be doing that modeset eventually anyway.
We used to do something similar, but then got piles of bug reports about the displays running at 30Hz rather than 60 so we changed it to 8. It's hard to say what a user will prefer.
"max bpc" is a maximum, ie. it shouldn't make a modeset fail, the kernel should automatically reduce the bpc if the link bandwidth is insufficient. So that sounds like there's an amdgpu bug here?
Yes, that's an amdgpu bug in my opinion too. A video mode is always explicit about timings, while "max bpc" is just a max and not "use this exactly", so I believe the explicit setting should win.
There is no "use this bpc exactly" KMS UAPI yet.
Thanks, pq