Bug 20478

Summary: [RADEON:KMS:X1100:PLL??] flickering after resume from ram
Product: xorg Reporter: Bryce Harrington <bryce>
Component: Driver/RadeonAssignee: xf86-video-ati maintainers <xorg-driver-ati>
Status: RESOLVED INVALID QA Contact: Xorg Project Team <xorg-team>
Severity: normal    
Priority: high CC: fabien_id, perper, swami
Version: 7.3 (2007.09)   
Hardware: Other   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:
Attachments:
Description Flags
Xorg.0.log none

Description Bryce Harrington 2009-03-05 01:10:39 UTC 
Created attachment 23555 [details] [review]
Xorg.0.log

Forwarding this bug from a Ubuntu reporter:
https://bugs.edge.launchpad.net/ubuntu/+source/xserver-xorg-video-ati/+bug/318325

[Problem]
After resuming from RAM, the screen flickers when the CPU load drops to a low level.

[Original Report]
System : Ubuntu 8.10 (up to date)
GPU : ATI express X1100
Video driver : radeon

Steps to reproduce :
- put the computer on standby
- resume from ram
=> the screen will flicker while CPU activity is not high

workaround :
- just launch an infinite loop that consume CPU : $ while true; do echo >/dev/null; done
=> the screen won't flicker while the CPU is use (even if only one core is being used)

There isn't error either in Xorg, xsession logs or in dmesg after resuming.

Notice that this trouble doesn't occur with fglrx driver.

[lspci]
00:00.0 0600: 1002:5950 (rev 10)
	Subsystem: 1025:009f
01:05.0 0300: 1002:5975
	Subsystem: 1025:009f
Comment 1 Piotr Krysik 2009-10-04 13:38:47 UTC 
It's not only appears after suspend to ram but also after suspend to disk. This problem is with us for very long. I think this is high time to solve this problem. I suppose that it will be hard to reproduce this problem on other machines so I can assist in tests. I know something about programming and debugging but I have zero knowledge about graphic drivers. I can follow instructions from someone experienced.
This is how screen exactly looks after suspend: http://www.youtube.com/watch?v=xuvfXgcQC94
Comment 2 Swâmi Petaramesh 2010-04-10 08:53:00 UTC 
Adding some more info at https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-ati/+bug/560104
Comment 3 Alex Deucher 2010-10-19 17:07:22 UTC 
Is this still an issue with KMS or an newer version of the driver?
Comment 4 fabien_id 2011-01-09 13:52:02 UTC 
Yes this is still an issue with KMS, as explain on launchpad's bug report:
https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-ati/+bug/318325
Comment 5 Jerome Glisse 2011-03-07 12:00:48 UTC 
This might be fixed with 2.6.38 (assuming it's pll related) once you have chance to test such kernel please report
Comment 6 Chris Koresko 2011-03-10 13:22:06 UTC 
Just tested this with a liveCD of Natty Alpha 3 x86 on my Acer Aspire 5100 (if memory serves; it's the machine I reported on elsewhere).  The problem is still there.  In fact, on resume the flickering starts immediately and is more frequent than before.

Looks like I'm stuck running Hardy on that machine.
Comment 7 Swâmi Petaramesh 2011-04-28 02:00:24 UTC 
Confirming, bug still present in Ubuntu Natty. Alas :-(
Comment 8 Christopher M. Penalver 2016-02-24 05:06:04 UTC 
Original reporter hasn't advised on results since Lucid (EOL as of May 9, 2013 as per https://wiki.ubuntu.com/Releases).
Comment 9 Tommy Trussell 2016-03-01 05:20:52 UTC 
Bug still exists in Ubuntu Wily.

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