Red Hat Bugzilla – Bug 839272
Xorg freezes when screen cable disconnected and reconnected again
Last modified: 2014-09-13 15:00:12 EDT
Description of problem:
I have [Quadro NVS 290] [10de:042f] with signal splitter into two screens. When I disconnects the primary one and reconnect it back X gets frozen in a while.
Keyboard is frozen as well as numlock is not reacting as well. I can get some response from the system over ssh. I can kill X and free keyboard but I cannot get X server back to show something .. need to reboot to get screen back.
will paste more logs and possibly gdb traceback
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1.disconnect primary screen from signal splitter cable
2.reconnect it back
whole computer frozen (keyboard, no screen)
no freeze.. computer back to normal
it needs to be primary screen, secondary is working as expected
Created attachment 597575 [details]
Created attachment 597576 [details]
I can reproduce this bug on Quadro 600 with first monitor connected to single-link DVI and second to DisplayPort with DVI adapter.
I have another two scenarios:
1) When I disable primary monitor in Control Center and then enable, Xorg freezes. It doesn't depend only on HW disconnect.
2) When I boot with only one monitor and then I connect second monitor, Xorg freezes too.
HW (dis)connect scenario is not reproducible with 2 VGA outputs*, only with scenarion 1 above.
*It does nothing automatically, must be enabled by Control Center, like in scenario 1.
GPU: NVS 300 with dual-link DVI to 2x VGA adapter
I can reproduce this bug only in Gnome Shell or GDM login screen. KDE and VT does not triger this bug,
I've found a workaround when second monitor is connected, but disabled. Switch to VT, wait for second monitor to show console, then switch back to Gnome Shell and enable second monitor.
Bug is reproducible with these nVidia cards and setups (always 2 monitors):
Quadro 600 with DVI and DP to DVI adapter
NVS 300 with dual-link DVI to 2x DVI adapter
Quadro 400 with DVI and DP to DVI adapter
Quadro NVS 295 with 2x DP to DVI adapter
NVS 300 with dual-link DVI to 2x VGA adapter
Can you retest with Alpha 3 and report back?
this is definitely still there and affecting all cards not just this one.
This needs retesting once an el7 kernel with updated DRM is available. The relevant paths changed significantly, and issues similar to these were fixed in the process. Hopefully that means this one is already too :)
Retested on the latest RHEL7 nightly by several disconnect/connect cycles (using a VGA splitter) and it seems like this issue is already resolved.
To be precise, the only exception is when I disconnect the monitor and then connect it back but to the other of the two VGA outputs on the splitter. In such case the monitor won't power on automatically but switching to a VT and back using CTRL-ALT-Fx combo does the trick. This is not a big issue I think and probably not related to this BZ, so I suggest to close as VERIFIED.
Also re-tested Comment 3 and everything went smooth.
This request was resolved in Red Hat Enterprise Linux 7.0.
Contact your manager or support representative in case you have further questions about the request.