The KDE screen kept hanging every few seconds , and it drove me crazy,
another error I've been seeing is in the messages log:
On Kernel 2.8.38: /sys/module/
i915/parameters /semaphores is set to 0
On Kernel 2.8.39: /sys/module/
i915/parameters /semaphores is set to 1
if i do the following:
echo 1 > /sys/module/
The Bug is also gone on 2.8.38 …..
If i set semaphores on 2.8.39 to 0 as it is default on 2.8.38, the bug also appears.
also there is a comment there talkeing about setting it up in boot through grub (I didnt test this yet though):
you can put this option in /etc/default/grub to make the change permanent
replace following line:
LINUX_DEFAULT= "quiet splash"
LINUX_DEFAULT= "quiet splash i915.semaphores=1"
now my KDE runs just fine
fix for the autoboot suggestion:
it didnt work, a working solution was to edit the /boot/grub/menu.lst file and add i915.semaphores=1 to the end of the kernel line.