Strange redisplay problems with Xorg 7.4 and intel driver

[Brian Rogers]

Tassilo Horn wrote:
> Hi all,
>
> I use Xorg 7.4 with the free intel driver (2.4.2) on a Lenovo/IBM
> ThinkPad T61.  For more than a month I suffer from heavy redisplay
> problems, for example:
>
>   - I close a window, but it's still displayed.  When I move another
>     window over it, it'll be erased.  (It's like cleaning a chalkboard.)
>
>   - I follow a link in a webbrowser, but the old page is still
>     displayed.  In order to see the new one, I have to move the window.
>
>   - I compile something in a terminal and some lines are not refreshed.
>     Again, moving the window forces a redisplay.
>   
I've seen this too. It's the framebuffer compression code missing some 
screen updates for some reason. You can solve the problem by disabling 
framebuffer compression. Just put this in your Device section:

Option "FramebufferCompression" "off"

Actually, I just found a bug filed for this: 
https://bugs.freedesktop.org/show_bug.cgi?id=16257
> What's interesting: Whenever I plug a second monitor and use it with
> Xrandr, the problem is gone.  It only occurs when I solely use the
> notebooks TFT.
>   
Yeah, that's because framebuffer compression can only work on the 
internal display.