Ubuntu
xserver-xorg-video-intel package

  1. Bug #541511
  2. Comment #34

Comment 34 for bug 541511

Revision history for this message
In , Daniel-ffwll (daniel-ffwll) wrote :

> --- Comment #32 from legolas558 <email address hidden> 2010-03-26 03:19:48 PST ---
> Created an attachment (id=34474)
> --> (http://bugs.freedesktop.org/attachment.cgi?id=34474)
> debugfs dumps after 2 failures with v6 patch
>
> I have just tested v6 patch with 3 glxgears and I got 2 flush failures; it is
> not possible to state if anything sensibly changed when compared with previous
> patch

Indeed, not much changed at all. The real problem is reported in the first
backtrace (grep for "chipset flush timed out" in your dmesg). It
essentially means that the code has given up. All further failed flushes
are most likely just a result of this.

The problem seems to be writes to the gtt just don't show up at the cpu
side on your box. There's a tunable in my patch in the file
drivers/char/agp/intel-gtt.c

#define I830_GTT_MAX_RETRIES 100

Can you try out whether increasing this to a ridiculous number (like 1000)
helps? This might cause your machine to stall sometimes. As soon as you
get the chipset flush timed out message (and the max retries hits the
value you've defined), give up.

Thanks alot for testing this stuff.

btw, has video stability increased further with v6?