Bug 113891

Summary:	[radeon] Display jitter
Product:	Drivers	Reporter:	Jean Delvare (jdelvare)
Component:	Video(DRI - non Intel)	Assignee:	drivers_video-dri
Status:	RESOLVED CODE_FIX
Severity:	high	CC:	alexdeucher, szg00000
Priority:	P1
Hardware:	x86-64
OS:	Linux
Kernel Version:	4.4.4, 4.5-rc7	Subsystem:
Regression:	Yes	Bisected commit-id:

Description Jean Delvare 2016-03-07 14:29:01 UTC

Since updating to kernel v4.4.4 (from v4.4.3), I get vertical jitter on my display with almost every boot. The picture moves up and down with black horizontal stripes. This makes the system pretty much unusable.

I bisected it to the following commit:

http://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/?h=linux-4.4.y&id=a83b349814dee660caff0a40a22ac2f166c94a8b

drm/radeon/pm: adjust display configuration after powerstate

I am now running v4.4.4 with this commit reverted and so far so good. My hardware:

01:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Turks XT [Radeon HD 6670/7670] [1002:6758] (Sapphire HD 6670)

Comment 1 Jean Delvare 2016-03-08 08:46:29 UTC

Kernel v4.5-rc7 is affected too.

Comment 2 Alex Deucher 2016-03-08 16:33:20 UTC

I'll just revert it for now.  Sorry for the breakage.

Comment 3 Jean Delvare 2016-03-09 09:42:00 UTC

OK, thanks Alex.