Screen contamination

[dark_mail at gmx.net]

Am 23.04.2011 02:42, schrieb gene heskett:
> On Friday, April 22, 2011 08:40:50 PM dark_mail at gmx.net did opine:
> 
>> Am 22.04.2011 23:00, schrieb gene heskett:
>>> Greetings folks;
>>>
>>> I have a problem.  Anytime I spend some time watching a news video on
>>> say fox or cnn's sites, I wind up with screen background
>>> contamination in my console windows of other workspaces.  Bit and
>>> pieces show up on the bottom half of such a terminal window, remain
>>> stationary on the screen as the terminal window is moved about, but
>>> are constrained by the border when the terminal is moved, but comes
>>> right back as soon as the terminal windows border encompasses that
>>> area of the screen again.
>>>
>>> Using FF4.0 and a pclos repo supplied kernel version 2.6.38.2, on
>>> pclos, on a quad core phenom, 4Gb of dram, and the latest .44 version
>>> of the dkms installed nvidia-current driver on a 9400 series nvidia
>>> card.
>>>
>>> FWIW, I recall seeing that also when I switched to the vesa driver, so
>>> while it could be related, I am dubious.
>>>
>>> What can I do to facilitate narrowing this down?
>>>
>>> Thanks.
>>
>> I'm by no means an expert, but could you try and disable page flipping
>> in the xorg.conf or check if it's turned on in the first place?
>>
>> I ran into a similar looking issue with the switch to kernel 2.6.38,
>> which introduced KMS page flipping to my graphics card (radeon).
>>
>> Checking for page flipping:
>> "cat /var/log/Xorg.0.log | grep -i Pageflip"
>>
>> If it's reported as enabled, read on. :-)
>  
> It is a null return.

If you are using Ubuntu, it's logfile probably is /var/log/xorg.0.log
(notice the lower case 'x')

> 
>> In your xorg.conf, put the following line in the "Device" section,
>> reboot and check if the issue appears.
>>
>>
>> Section "Device"
>>
>>         Option  "EnablePageFlip"        "off"
>>
>> EndSection
>>
>> If turning it off helps, maybe you're also being hit by bug
>> https://bugs.freedesktop.org/show_bug.cgi?id=35452
>>
>> This one is about the ati driver, though. So maybe it's unrelated. I
>> hope I'm being helpful.
> 
> I wonder if there is a different name for it when using the nvidia driver?
> 
> Thanks.
> 
> 

I did some digging in the xorg.conf options list and found this:

Option "NoFlip" "boolean"

The description matches what EnablePageFlip does, except it's reverted,
which means setting "boolean" to "true" should turn off page flipping.
See if that makes a difference.