I have two displays attached to GTX980. When I enable ForceCompositionPipeline option in xorg.conf for both of them and reboot, I can see full system lockups at random times. The UI freezes, mouse isn’t moving, no reaction to keypresses, even SysReq+REISUB doesn’t always work. CPU fan starts to spin, so it sounds like it is a busy wait of some kind. The system is inaccessible from network as well (it may respond to pings for a few seconds after the hang but then not even that). Basically, I can only hard-reset the system at this point.
The lockups can happen at any time after boot. I’ve seen system hang within a few minutes after boot, during normal activity like browsing or watching a video, and after a few hours while the system was idle and the display was turned off due to powersaving (the system itself does not go to suspend mode).
Without the ForceCompositionPipeline option, all other config the same, lockups don’t happen. I have tested Linux kernels 4.10.17, 4.13, 4.15-rc9 - the hangs happen the same way on all of them. Nvidia driver 390.12.
Instead of /etc/X11/xorg.conf, I only have one 20-nvidia.conf file in /etc/X11/xorg.conf.d with this content:
Section "Device"
Identifier "Default nvidia Device"
Driver "nvidia"
Option "NoLogo" "True"
Option "CoolBits" "12"
Option "TripleBuffer" "True"
Option "MetaModes" "DP-4: nvidia-auto-select {ForceCompositionPipeline=On}, HDMI-0: nvidia-auto-select {ForceCompositionPipeline=On}"
Option "MetaModeOrientation" "RightOf"
# Option "UseEdidDpi" "False"
# Option "DPI" "162 x 161"
EndSection
When I comment out MetaModes and MetaModeOrientation the lockups no longer happen.
While testing kernel 4.15-rc9, I noticed a quite few soft lockup errors in the kernel log, some of them mentioning nvidia driver in the backtraces. I’m attaching the kernel log as well.
nvidia-bug-report.log.gz (123 KB)
kern_4.15.0rc9.log.gz (1.16 MB)