Created attachment 143174 [details]
System is Thinkpad T460p with external display attached over DisplayPort. Kernel is v5.0-rc2. Xorg is 1.20.3.
Xorg starts normally, but if external display gets through power cycle switching to console and back leads to Xorg crash with "modeset(0): failed to set mode: No such file or directory". See attached log.
The external display is Dell UP2414Q, which is 4k, but the bug can be reproduced with MST disabled too.
Created attachment 143175 [details]
dmesg with drm.debug=0x1e
Kirill - what WM/Desktop Environment are you using?
AwesomeWM as an window manager and SLiM as an login manager.
Thanks Kirill - could you also provide the output of:
both before and after the issue occurs?
Created attachment 143221 [details]
Created attachment 143222 [details]
Hmm - I wonder if this is the same issue as https://bugs.freedesktop.org/show_bug.cgi?id=88124
DK, what do you think?
I *think* you are right (but I would like somebody to confirm it). Connecting the display directly to the laptop solves the issue.
Is there any guidance on how window managers have to deal with this?
What's interesting is dmesg shows modeset on the new connector succeeded after vt switch. Can you please attach dmesg with drm.debug=0x1e, the file that's currently attached is with drm.debug=0xe? Also verbose xserver logging will be helpful.
(In reply to Kirill A. Shutemov from comment #8)
> I *think* you are right (but I would like somebody to confirm it).
> Connecting the display directly to the laptop solves the issue.
> Is there any guidance on how window managers have to deal with this?
Do you see the same problem if you power cycle the monitor by pressing the power button or hotplugging the monitor?
Created attachment 143245 [details]
dmesg with drm.debug=0x1e
Created attachment 143246 [details]
(In reply to Dhinakaran Pandiyan from comment #9)
> What's interesting is dmesg shows modeset on the new connector succeeded
> after vt switch.
Clarification: text console comes up normally, crash happens when I switch back to Xserver. Login manager gets Xserver restarted just after the crash.
(In reply to Dhinakaran Pandiyan from comment #10)
> Do you see the same problem if you power cycle the monitor by pressing the
> power button or hotplugging the monitor?
Display doesn't comes back after power cycle (goes to power saving mode), but Xserver doesn't crash at this point.
I have not tried hotplugging. I'll come back to you on this.
Hotplug behaves the same way as power cycling: display doesn't come back, but it doesn't crash Xserver either.
Kirill - We're having a bit of trouble replicating your error locally here. It appears that you're running Gentoo - if that's correct I'll try to build a replica system locally. Would you be able to post the following:
--The /var/lib/portage/world file
--The output of 'equery list "*"'
--The output of 'emerge --info"
--The /etc/portage/package.use file (or the files in that directory)
--The /etc/conf.d/xdm file
Created attachment 143255 [details]
Thanks Kirill - haven't been able to get a replica system up and running yet, I will let you know when that happens
DK, What are the next steps here? Verifying the issue with drm-tip will give more ideas?
Sorry, I got busy with other things.
Is the bug still reproducible?