Bug 61802 - [uxa] running Xorg -background none with plymouth causes a black screen flickering
Summary: [uxa] running Xorg -background none with plymouth causes a black screen flick...
Status: NEW
Alias: None
Product: xorg
Classification: Unclassified
Component: Driver/intel (show other bugs)
Version: unspecified
Hardware: Other All
: medium normal
Assignee: Chris Wilson
QA Contact: Intel GFX Bugs mailing list
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2013-03-04 16:33 UTC by Frederic Crozat
Modified: 2013-03-05 07:22 UTC (History)
1 user (show)

See Also:
i915 platform:
i915 features:


Attachments
drm.debug=6 dmesg output (75.29 KB, text/plain)
2013-03-04 16:54 UTC, Frederic Crozat
no flags Details

Note You need to log in before you can comment on or make changes to this bug.
Description Frederic Crozat 2013-03-04 16:33:12 UTC
This is with intel driver 2.20.19:
00:02.0 VGA compatible controller: Intel Corporation Atom Processor D4xx/D5xx/N4xx/N5xx Integrated Graphics Controller (prog-if 00 [VGA controller])

[    43.928] (--) intel(0): Integrated Graphics Chipset: Intel(R) Pineview GM

When X is being started by gdm, we get a black flickering, despite plymouth correctly retaining splash to prevent this flickering.
Comment 1 Chris Wilson 2013-03-04 16:42:11 UTC
"Correctly" may turn out to be an overstatement. Have you checked drm.debug=6 dmesg to see why the modeset is required?
Comment 2 Frederic Crozat 2013-03-04 16:54:42 UTC
Created attachment 75904 [details]
drm.debug=6 dmesg output

here is the logs.

I've noticed similar flicker on other intel platform, I'll give the debug output later.
Comment 3 Chris Wilson 2013-03-04 17:12:11 UTC
From the kernel perspective, everything worked fine. plymouth triggered a modeset and installed its fb, then X starts and just triggers a set-base rather than a full modeset. That should be seamless (at no point did we power down the pipe to make the changes).

So, the question then becomes did UXA render a visible black frame before filling it with the copy from fbcon?
Comment 4 Frederic Crozat 2013-03-04 17:26:30 UTC
(In reply to comment #3)

> So, the question then becomes did UXA render a visible black frame before
> filling it with the copy from fbcon?

Any way to debug this ?
Comment 5 Chris Wilson 2013-03-04 17:31:23 UTC
Using SNA, --enable-debug=full. Using UXA, switch to SNA... :|
Comment 6 Frederic Crozat 2013-03-04 17:39:22 UTC
(In reply to comment #5)
> Using SNA, --enable-debug=full. Using UXA, switch to SNA... :|

switching to SNA fixed the back flickering..

I'll test on the other hardware where I saw the bug before closing this bug.
Comment 7 Frederic Crozat 2013-03-05 07:22:18 UTC
ok, tested on another system :
00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09) (prog-if 00 [VGA controller])

Switching to SNA fixed the black flicker too..


Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.