[xubuntu-users] Graphic card disaster

[Dave Dodge]

On Tue, Feb 25, 2014 at 10:17:01AM -0300, Bruno Benitez wrote:
> Michele, remember that you can always revert to the generic video drivers
> by renaming/removing the /etc/X11/xorg.conf file, regardles of the
> installed drivers if xorg.conf is ausent the system will use the default
> ones.

I don't think that works with recent X servers.  X.Org is a lot better
at automatically configuring things than it used to be.  The system
I'm typing this on is Xubuntu 13.10 with no xorg.conf, but it still
auto-detects and uses the proprietary fglrx drivers.  I installed the
AMD beta drivers from .deb files earlier today.

When I was setting it up I did switch back and forth between the
proprietary fglrx drivers and the open source radeon driver several
times.  To go back to the radeon driver I purged the fglrx packages
from a text console (while not logged into the X server):

  sudo /etc/init.d/lightdm stop
  sudo apt-get purge 'fglrx*'

Then when I rebooted, the system automatically detected and used the
radeon driver instead.  To go back to the fglrx drivers I just
reinstalled the deb files and rebooted:

  sudo /etc/init.d/lightdm stop
  sudo dpkg -i fglrx*deb

At no point did I have an xorg.conf.  In fact I removed the old one
before starting the upgrades this morning because I wanted to make
sure my old forced configuration didn't get in the way.


BTW I found that with the AMD 14.2 beta drivers, OpenGL games and
various other things seemed to work, but starting Firefox would
instantly segfault the X server every time.  The stock AppArmor
configuration apparently doesn't allow Firefox to access some new(?)
fglrx-related files.  My workaround was to put some additional rules
into /etc/apparmor.d/local/usr.bin.firefox:

  # When using Catalyst 14.2 beta, Firefox needs to be able to access a
  # bunch of device-related files.  Otherwise it can end up crashing the
  # X server.
  /proc/modules r,
  /proc/ati/** r,
  /dev/ati/card* rw,
  /run/shm/ParseLock* rw,

And then update the configuration:

  sudo aa-enforce /etc/apparmor.d/usr.bin.firefox
  sudo service apparmor reload

After that Firefox appears to run without any complaints in dmesg, and
at least the X server isn't crashing.

                              -Dave Dodge/dododge at dododge.net