some of the MacBookPro 14,3 users have been struggling with the black screen issue on their systems, I have been bisecting the kernel commits that came to v4.18-rc1 and found that the problem is gone when I revert this commit "drm/amd/display: Do not limit color depth to 8bpc" e03fd3f300f6184c1264186a4c815e93bf658abb
I presume that the driver cannot get the display_info.bpc from the screen so it defaults to COLOR_DEPTH_UNDEFINED causing the black screen.
Please let me know,
P.S. I have been sending an email to Harry Wentland & Alex Deucher on 18 Sept. 2018, but no response followed.
I can confirm the bug. We provide an exam environment based on Debian Live. Since we switched to Kernel 4.18 (provided in Debian backports) we have seen *many* Macs failing to boot and just showing a black screen. So at least for us this regression is quite severe...
This patchset may help:
(In reply to Alex Deucher from comment #2)
> This patchset may help:
Thank you, Alex.
I can confirm, the patches worked for me.
I have adapted them for Linux 4.19.2 - https://gist.github.com/arno01/8115ef124fe7f42bbf1c317892013e86
Any plans for including them in the next Linux release?
(In reply to Andrey Arapov from comment #3)
> (In reply to Alex Deucher from comment #2)
> > This patchset may help:
> > https://patchwork.freedesktop.org/series/52164/
> Thank you, Alex.
> I can confirm, the patches worked for me.
> I have adapted them for Linux 4.19.2 -
> Any plans for including them in the next Linux release?
yes. They should land in 4.20 soon.
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