Problems with two ATI cards, in recent X versions
kilgota at banach.math.auburn.edu
Thu Aug 23 16:27:21 PDT 2012
The first machine has in it the following on-board video:
01:05.0 VGA compatible controller: Advanced Micro Devices [AMD] nee ATI
RS780 [Radeon HD 3200]
The problem with it is that mode switching does not work right.
Before giving details of what happens, let me explain that I have poor
eyesight. Thus, I like to drop down to a lower resolution than what is
default in order to be able to read better any text on the screen. I often
do this, for example, with web pages in the browser and also when doing
something in an xterm. The max resolution of my monitor is 1920x1080. I
often prefer to drop the resolution back to 800x600. Kernel mode switching
is enabled, and I have a script written, which contains
if [ "$DISPLAY" = "" ]
then echo "No display. Exiting."
OUTPUT=`xrandr -q |grep " connected"|cut -d' ' -f 1`
xrandr --fb 1920x1080 --output $OUTPUT --mode 1920x1080 --panning
As you can see, it is intended that the "panning" dimensions ought to
remain at 1920x1080 so that by moving the mouse here or there it is
possible to see any part of the desktop which is outside of the 800x600
window, or, one might say, to be able to move the 800x600 "magnified"
window to any part of the 1920x1080 desktop.
Several X versions ago, this used to work. But then it quit working. What
happens instead is that, if the script is run while the mouse cursor is
near the bottom right of the screen all is OK. One can move to the left
and or move up, and the 800x600 window follows the mouse. But once one has
done that, the 800x600 window is frozen in place and cannot be moved back
downward, or back to the right.
Experimentation has caused me to suspect that the problem is in the ATI
driver code somewhere, or in the radeon driver code. Hence this message to
the xorg-driver-ati list. Meanwhile, I am forced to run an older version
of X-practically-everything in order to try to work around this problem.
This becomes increasingly difficult, as new versions of various kinds of
software (the latest Firefox, for example) seem to have dependencies on
newer versions of X-related libraries.
The other machine is slightly older than the one described above, and it
has an even worse problem. It has in it an on-board video which lspci
01:05.0 VGA compatible controller: ATI Technologies Inc RS690 [Radeon
With this machine, the problem is that it is impossible to stop X once it
is started. At worst, the machine can be frozen with a blank screen and an
apparent kernel panic, causing the machine to be totally unresponsive to
any action except to hit the power button.
Again, with this second machine the only "cure" to the problem is the
unsatisfactory one, which is to stick with an old version of X-everything
which permits the machine to run normally.
Unfortunately, I did not keep records of exactly at what point or at which
versions of what related packages these problems started to occur with
either machine, but I could, of course, report the versions which are
known to work and which I am currently using.
More information about the xorg-driver-ati