Bug#540954: video-radeon: white flashing lines when moving cursor between screens

[Alex Deucher <alexdeucher@gmail.com>]

On Thu, Aug 13, 2009 at 5:18 PM, Michal Suchanek<hramrach@centrum.cz> wrote:
> 2009/8/11 Alex Deucher <alexdeucher@gmail.com>:
>> On Mon, Aug 10, 2009 at 6:53 PM, Michal Suchanek<hramrach@centrum.cz> wrote:
>>> Package: xserver-xorg-video-radeon Version: 1:6.12.2-3 Severity: minor File: video-radeon In a two screen setup wnenever I move the mouse cursor between screens pieces of horizontal white lines appear momentarily at random on the right edge of the primary screen. The secondary screen is right of the primary and rotated. I suspect it is specific to this hardware because the lines are quite easily noticed with light web page background and dark scrollbar in Firefox - it seems the web page is bleeding into the scrollbar. I was unable to reproduce this in a terminal or on the smaller screen so it might be also specific to the way Firefox redraws its window. Yes, there is no reason to redraw but like it would stop Mozilla products from redrawing. I did not notice this issue with Radeon X550 card and slightly older X server - had to restart it when replacing the card.
>>
>> Can you try xf86-video-ati from git master?  This sounds like a
>> display watermark issue.
>
> Same results with yesterday's git master.
>
> The flashing lines occurs on the (physical) right of both screens
> while Firefox is redrawing, especially while loading a web page. On
> the smaller screen the right side is the logical top which typically
> contains some menus or toolbars so the effect is not so easily
> noticed.
>
> It happens even when Firefox is not mapped (ie if  I restart Firefox
> which causes page loading and switch to a different desktop the lines
> appear on the visible desktop.
>

Does
Option "DisplayPriority" "HIGH"
in the device section of your config help?  Also, if you have a large
virtual setting in your config:
Virtual 2304 2304
reducing that might as help as well if you don't need all of it.
And finally, you might try disabling tiling:
Option "ColorTiling" "FALSE"

Alex