Mesa: texture_from_pixmap outputs white patch

[Michel Dänzer]

On Thu, 2008-07-17 at 16:46 -0700, Mohan Parthasarathy wrote:
>  
>         
>         > I am using ATI Radeon 1650 PRO. ./texture_from_pixmap (with
>         > LIBGL_ALWAYS_INDIRECT=1) works properly when compiz is not
>         running i.e
>         > i can see the complete picture being drawn. When compiz is
>         running,
>         > several things happened.
>         >
>         > 1) First time, i started texture_from_pixmap i got logged
>         out and had
>         > to login back ..
>         
>         
>         Sounds like the X server crashed, if this is reproducible it
>         would be
>         good to track it down
>  
> This can be reproduced by just running texture_from_pixmap in a tight
> loop. At least i can reproduce it.

Good, can you get a gdb backtrace from the X server crash?


>         > 2) Second time, the window is drawn and as i resize i can
>         see the
>         > rectangles and the diagonal lines inside being
>         >      drawn but when the resize ends, i can't see anything.
>         
>         
>         That's probably because GL rendering isn't properly redirected
>         without
>         DRI2.
>         
> 
> Do you mean to say that it just works by luck when i run compiz :-)

Kind of; without DRI2, the application is racing with compiz for the
visible screen buffer instead of rendering to the window's backing
pixmap used by compiz as a texture.


> Also, with DRI2, what version of the linux kernel i should be
> running ? 

I'm not sure, but I don't think it has any direct requirement on the
kernel version.


-- 
Earthling Michel Dänzer           |          http://tungstengraphics.com
Libre software enthusiast         |          Debian, X and DRI developer