Bug 34579

Summary:	Second Head on Radeon Mobility X1400 Flashes on and off at intervals
Product:	xorg	Reporter:	Kristoffer Tangfelt <revellion>
Component:	Driver/Radeon	Assignee:	xf86-video-ati maintainers <xorg-driver-ati>
Status:	RESOLVED INVALID	QA Contact:	Xorg Project Team <xorg-team>
Severity:	major
Priority:	medium	CC:	revellion
Version:	unspecified
Hardware:	x86-64 (AMD64)
OS:	Linux (All)
URL:	http://bambuser.com/channel/revellion/broadcast/1440695
Whiteboard:
i915 platform:		i915 features:

Description Kristoffer Tangfelt 2011-02-22 11:00:47 UTC

Using my laptops internal panel works fine but once i turn on the second head it works fine for about 10-20 secs then it flashes off and on.. then it goes another 10-20 sec and the same happens again. 

I have filmed the bug with bambuser from my HTC Desire to show it.

http://bambuser.com/channel/revellion/broadcast/1440695

As a comparison this bug is not visible on my desktop workstations double monitor setup. where the bug is not happening. only difference in these systems are..

Desktop Workstation: ATI Radeon HD3870 AGP (rv615), 32Bit ArchLinux
Laptop: ATI Mobility Radeon X1400 PCIE (rv515), 64Bit ArchLinux

Both using the drm-latest-testing kernel at 2.6.38-rc5. but the bug is also noticed on stock 2.6.37.1 kernel for the laptop.

So something that is related to the r500 GPU is bugging the monitors. where as it works just fine on the r600 based card in the Desktop.

Comment 1 Kristoffer Tangfelt 2011-02-22 11:01:37 UTC

xf86-video-ati version is 6.14 if that is important to note.

Comment 2 Alex Deucher 2011-02-22 11:31:46 UTC

Does disabling pageflipping help?
Option "EnablePageFlip" "False"
in the device section of your xorg.conf.

Some people have reported that upowerd and knotify poll the displays at regular intervals which can cause display glitches.  Killing upowerd or knotify should fix it if that is the cause.

Comment 3 Adam Jackson 2018-06-12 19:10:34 UTC

Mass closure: This bug has been untouched for more than six years, and is not
obviously still valid. Please reopen this bug or file a new report if you continue to experience issues with current releases.

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