Bug 100973

Summary: [SKL][Regression] Dell monitor stays black until GDM restart
Product: DRI Reporter: Paul Menzel <pmenzel+bugs.freedesktop.org>
Component: DRM/IntelAssignee: Intel GFX Bugs mailing list <intel-gfx-bugs>
Status: CLOSED WORKSFORME QA Contact: Intel GFX Bugs mailing list <intel-gfx-bugs>
Severity: normal    
Priority: medium CC: intel-gfx-bugs
Version: DRI git   
Hardware: Other   
OS: All   
Whiteboard:
i915 platform: SKL i915 features: display/Other
Attachments:
Description Flags
journalctl -k -o short-precise none

Description Paul Menzel 2017-05-08 16:14:21 UTC 
Created attachment 131263 [details]
journalctl -k -o short-precise

Testing Linux 4.11, there is a regression compared to Linux 4.9.25 and 4.11-rc5. The hardware is HD Graphics 530 and a Dell UP3214Q monitor.

Not even the Linux messages can be seen in the beginning. Restarting GDM with `sudo systemctl restart gdm.service` didn’t help, and the monitor seems to be stuck in a state, where it has to be forcefully powered off by pressing the power button for ten seconds, and then turning it back on. Then it goes into power saving mode, and then restarting GDM works.

```
$ lspci -s 0:02.0 -nn
00:02.0 VGA compatible controller [0300]: Intel Corporation HD Graphics 530 [8086:1912] (rev 06)
```

Please find the Linux messages with `drm.debug=0x1e` attached [1].


[1] https://01.org/linuxgraphics/documentation/how-report-bugs
Comment 1 Ricardo 2017-05-09 20:47:35 UTC 
Triage needed to identify i915 Feature
Comment 2 Elizabeth 2017-07-05 15:02:49 UTC 
(In reply to Paul Menzel from comment #0)
> Created attachment 131263 [details]
> journalctl -k -o short-precise
> 
Hello Paul, 
Is the problem reproducible with 4.12?

> Testing Linux 4.11, there is a regression compared to Linux 4.9.25 and
> 4.11-rc5. The hardware is HD Graphics 530 and a Dell UP3214Q monitor.
>
Comment 3 Paul Menzel 2017-07-06 15:54:01 UTC 
(In reply to Elizabeth from comment #2)
> (In reply to Paul Menzel from comment #0)
> > Created attachment 131263 [details]
> > journalctl -k -o short-precise
>
> Is the problem reproducible with 4.12?

No, that exact problem is not reproducible anymore in Linux 4.11.9 and 4.12. I do not know, when it was fixed.

There are still problems with that monitor though, so I do not know anymore if that was a special behavior of the monitor or the Linux kernel.

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