Ubuntu
xserver-xorg-video-ati package

  1. Bug #363238
  2. Comment #103

Comment 103 for bug 363238

Revision history for this message
psfblair (ciriwe) wrote : Re: very poor Xorg performance on various older graphics HW - XAA solves this

I figured out my issue with getting software rasterization -- it was the permissions on the device. Based on this bug report here:

http://bugs.freedesktop.org/show_bug.cgi?id=19492

I tried both "glxinfo" and "sudo glxinfo" and noted that in the former case I got software rasterization, while in the latter case I was getting "Mesa DRI Radeon..." As recommended in that bug report I set the permissions on /dev/dri/card0 to 0666 and am now getting Mesa DRI when I'm not the root user as well. Now EXA acceleration seems to be working quite well.

Martin Olsson wrote:

> @Rolf, note that loading the glx module explicitly doesn't do anything for recent X.org
> versions (it's autoloaded and so is "dri" module). Further, the permissions on the dri
> device node are also no longer in use because that device now has an ACL on it (so the
> "Mode 0666" stuff is obsolete). If you do "ls -l /dev/dri/card0" you will notice that the
> permissions have a small "+" char next to it, that indicates the presence of an ACL.
> You can see the ACL using the command "getfacl /dev/dri/card0".

Interestingly, the permissions on the dri device node apparently still do have some relevance; at least they made a big difference in my case. Is there perhaps a bug lurking here?