Saturday, December 02, 2006

A fix for Radeon Xpress lockups under X.org

I'm writing this article so that people googling can find the fix.

I just helped some fellow UNSW students fix Linux hanging when performing a graphical login (no, even the magic sysrq keys I enabled did not help). They were running X.org 6.8.2 (Fedora Core 4) with an ATI X600 graphics card (Dell Optiplex GX620).

I solved this by switching from the buggy opensource radeon driver to the generic VESA driver i.e. in /etc/X11/xorg.conf under Section "Device", I changed:

Driver "radeon"

to

Driver "vesa"

There are also 2 other solutions that apparently work:

1. Richard Zach suggests using the binary ATI driver.

2. Those students found that the opensource radeon driver worked if they updated to X.org X11R7 (Fedora Core 5) [*]. Unfortunately, they need to run some closed-source software that only supports Fedora Core 4. Furthermore, this upgrade does not seem to help with an ATI X200, which experiences similar lockups.

[*] Does anyone know the exact version X.org number?

3 comments:

Jiilik said...

I had this problem a long time ago, before I switched to the fglrx drivers. I used the X200 chipset and it hard locked at kdm on boot. Here's my fix from months and months ago:

In xorg.conf, under the 'ati' driver section, enter in Option "NoAccel" "true" and the ati drivers will work

Hal said...

Oh man, I dunno if that is really such a good fix. Using the 'vesa' driver with an x600 is pretty seriously painful. To scroll a window down to read the next paragraph in your web-browser involves an ugly one second wait while the screen updates line by line. If you're in the habbit of using the down arrow to scroll a little bit at a time it really sucks. I'm using the radeon driver that ships with debian unstable and the 2.6.16-2-686-smp kernel and it works ok.
fglrx seems to invite a world of pain.

Clarence Dang said...

jiilik: Thanks for the tips, will try both out (the binary driver and NoAccel)

hal: I didn't use the X600 much but using the vesa driver, it didn't seem _that_ slow.