https://bugs.freedesktop.org/show_bug.cgi?id=110371
--- Comment #5 from Nicholas Kazlauskas nicholas.kazlauskas@amd.com --- (In reply to Michel Dänzer from comment #4)
(In reply to Nicholas Kazlauskas from comment #3)
It's hitting the "." as part of the video mode and erroring out because DRM doesn't consider it a valid character.
Or maybe there's two separate issues? Failure to parse the mode name shouldn't affect whether or not DC picks up EDID, should it?
I suppose that doesn't actually influence whether the EDID has been read or is valid. So that's a different bug.
The "No EDID read." error comes from the result from drm_get_edid(...) being NULL, however.
While we're responsible for the actual transfers to and from the receiver the actual logic is shared there between drivers.
(In reply to Babblebones from comment #2)
Created attachment 143957 [details] Dmesg output from an affected kernel
Here is the issue, you can see [ 1.335096] [drm:dc_link_detect [amdgpu]] *ERROR* No EDID read.
Which is about where the display turns into fruit salad. Please let me know if I can submit any more debug info that would assist! I am very much in need of running a newer kernel.
Can you post a dmesg log with drm.debug=4 as part of your kernel boot parameters?