Bug 109610

Summary: display corruption on ctrl-alt-F3
Product: DRI Reporter: Luigi Cantoni <lui>
Component: DRM/IntelAssignee: Intel GFX Bugs mailing list <intel-gfx-bugs>
Status: RESOLVED FIXED QA Contact: Intel GFX Bugs mailing list <intel-gfx-bugs>
Severity: normal    
Priority: medium CC: intel-gfx-bugs
Version: unspecified   
Hardware: Other   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:
Attachments:
Description Flags
Corrupted image on ctrl-alt-F3 none

Description Luigi Cantoni 2019-02-12 00:10:29 UTC
Created attachment 143362 [details]
Corrupted image on ctrl-alt-F3

System boots normally for kernel 4.20.
I have several systems
1) ASUS mother board with a Pentium CPU (3-5 years old)
2) Gigabyte Z370M-D3H LGA1151-CL Mother board with I5 CPU (1-2 years old)
3) MSI B360M Gaming Plus DDR4 Turbo M2 LGA1151 Mother board with I5 CPU (several months old)
4) MSI H310M PRO-VD LGA1151 Mother board with I3 CPU (weeks old)

ASUS does not show the problem while the other three do.
Disk drive is the same one so image is identical.

It has been suggest the i915 is the issue.

If I have ctrl-alt-F1 with the graphical login screen
ctrl-alt-F2 is a logged in session
ctrl-alt-F3 is the character based login. This is the screen display with the problem visible on it.

Swap from F1<->F3 100% looks OK
Swap F1<->F2 100% OK (always was and never had an issue)
Swap F2<->F3 and my problem is there.
Do F2->F3 (problem there) do F3->F1->F3 problem not there
Or do F2->F1->F3 problem not there.
It fixes up the display if I go through the F1 (graphical login) screen.

Also something I have noticed is that when I swap out of F2 for a moment the screen goes silly in the top left with the graphical data and F3 does not clear it but F1 seams to clear it out.

My guess is the swap screen code is writing the data out (maybe only as temporary buffer) and F1 (as an initialization code) clear that temporary area out) and that is what is happening and why F1 fixes it.

I tried various things to do with xorg/wayland etc (I was doing my tests wrong)
and this is what I have finally found.

Some more testing:
with /etc/gdm/custom.conf having these lines in the daamon section
[daemon]
WaylandEnable=true
DefaultSession=gnome-xorg.desktop

and selecting from the login cog either "gnome classic" or "gnome on xorg" it continues to fail.
If you choose "gnome" (which I had not done before) it appears to be OK. Certainly the ways I was doing before to make it fail does not appear to fail.
I have rebooted etc and behaviour does not change.

The reasons I like "gnome classic" is the pull down "Applications" menus and also the "minimize, full screen etc" at the top of the active window, also the small icon display of all the windows on the screen is nice. Can anyone say if there is anyway I can get that with new gnome version (I think not).

Happy to do any tests (config etc) people suggest (I don't build kernels and code though).
Comment 1 Denis 2019-02-12 10:11:16 UTC
hi, everything you wrote sounds very similar to these issues:

https://bugs.freedesktop.org/show_bug.cgi?id=107951
https://bugs.freedesktop.org/show_bug.cgi?id=106478
https://bugs.freedesktop.org/show_bug.cgi?id=108257

and here is a link to patch series which fixed this issue:
https://patchwork.freedesktop.org/series/51878/

Available in drm-tip from intel, and not sure about main kernel source.
Comment 2 Denis 2019-02-12 10:18:48 UTC
upd

found one of mentioned patches in torvalds/linux

https://github.com/torvalds/linux/commit/8315847bf4df9290042f0d8bce3b1a2d303afe80

According to the tag, these patches available on v5.0-rc6, or, as I said higher - in drm-tip from intel.
Comment 3 Luigi Cantoni 2019-02-13 00:15:28 UTC
Thanks Denis for your research,
I agree looks like the same bug (sometimes showing up a bit differently).
I don't do kernel patches so I won't try the patch suggested.
As it appears V5 of the kernel will fix it and I don't believe it will cause me any really strange problems I am happy to live with the bug until then.

Great to see its fixed.
This item is thus CLOSED/RESOLVED.

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