https://bugzilla.kernel.org/show_bug.cgi?id=211033
Bug ID: 211033 Summary: [bisected][regression] amdgpu: *ERROR* Restoring old state failed with -12 Product: Drivers Version: 2.5 Kernel Version: 5.10.4 Hardware: x86-64 OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: Video(DRI - non Intel) Assignee: drivers_video-dri@kernel-bugs.osdl.org Reporter: zaltys@inbox.ru Regression: No
I have AMD RX560 GPU which is connected to LG 27UD-88 display via ATEN CS782DP displayPort KVM switch.
I can't reliably switch KVM port to the machine running Kernel 5.10.4 with previously mentioned GPU. Screen is usually blank and display even goes to standby after the first try, however sometimes (if I switch KVM ports quickly a few times) it turns on, but with wrong resolution. dmesg complains with:
[drm:dm_restore_drm_connector_state] *ERROR* Restoring old state failed with -12
for every failed port switch.
KVM switch is configured to "redetect display" - basically it emulates replugging when port is switched. I have been using it for 4 years with the same GPU and it worked correctly until Kernel 5.10.4
I did a bisect, and it showed the first bad commit was: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/driv...
Reverting this commit fixed my issue (it works like pre 5.10.4)