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https://wiki.archlinux.org/title/Bug_reporting_guidelines
Do NOT report bugs when a package is just outdated, or it is in the AUR. Use the 'flag out of date' link on the package page, or the Mailing List.
REPEAT: Do NOT report bugs for outdated packages!
FS#70941 - DisplayPort signal over USB-C no longer appears to be working with kernel 5.12.4
Attached to Project:
Arch Linux
Opened by Robert Strube (rstrube) - Tuesday, 18 May 2021, 22:35 GMT
Last edited by Jan Alexander Steffens (heftig) - Friday, 21 May 2021, 08:17 GMT
Opened by Robert Strube (rstrube) - Tuesday, 18 May 2021, 22:35 GMT
Last edited by Jan Alexander Steffens (heftig) - Friday, 21 May 2021, 08:17 GMT
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DetailsDescription: DisplayPort signal over USB-C no longer appears to be working with kernel 5.12.4.
I have an external display that is both powered and receives a DisplayPort signal over USB-C to USB-C cable. I recently upgraded to kernel 5.12.4 and the monitor will no longer receive a signal. It does continue to receive power over USB-C. I booted up a live ISO of another Linux distribution (Fedora) on the same system and the monitor works fine. Fedora is currently using kernel 5.11.x. I have also tested this issue with other monitors using a USB-C to DisplayPort cable, and the problem exhibits itself with those monitors as well. I have tested both the regular linux package and linux-zen and both exhibit the same problems. It's worth noting that when I upgrade my kernel, the amd-ucode and linux-firmware packages were also updated. So it's possible this might have had an effect. Additional info: * My system has an AMD 4800U APU and only uses the iGPU that comes with the CPU (i.e. no additional dedicated GPU). * Appears to affect linux, linux-zen > 5.12.4 * Current kernel: 5.12.4-zen1-2-zen Steps to reproduce: * Install the latest kernel * Plugin a monitor via USB-C (that supports Displayport over USB-C) * The monitor will not receive a signal and nothing is displayed on the monitor |
This task depends upon
Closed by Jan Alexander Steffens (heftig)
Friday, 21 May 2021, 08:17 GMT
Reason for closing: Deferred
Additional comments about closing: Upstream issue was closed, saying it isn't the kernel and more research is needed.
Friday, 21 May 2021, 08:17 GMT
Reason for closing: Deferred
Additional comments about closing: Upstream issue was closed, saying it isn't the kernel and more research is needed.
Comment by Robert Strube (rstrube) -
Thursday, 20 May 2021, 05:21 GMT
Issue is still present with kernel 5.12.5.
Comment by Robert Strube (rstrube) -
Thursday, 20 May 2021, 06:02 GMT
I opened up an upstream bug report with AMD here: https://gitlab.freedesktop.org/drm/amd/-/issues/1601