John's Blog

For quite a long time Intel has been the shining light of open source video drivers on Linux. Even though Intel integrated video doesn’t have the highest performance it was what you needed to have for full 3D support, and fancy splash screens when booting with (plymouth). By no means were the drivers ever perfect but they actually worked for the majority of people. That is until Kernel 2.6.34, Xorg 1.8 and the 2.12.0 Intel driver were released. There are really two different sets of issues I’ve experienced. One relates to Kernel 2.6.34 and the other is with Xorg 1.8 and video-intel 2.12.0.

With Kernel 2.6.34 suspend stopped working properly. At first I thought that the ACPI suspend patches for my notebook that were added years(?) ago had been reverted. The symptoms were the same as before Linux was able to suspend properly with my notebook. Instead of suspending the system would lockup, the screen would be blank and the fan would run at its maximum speed. The suspend code for my notebook was still present in 2.6.34 so I was at a bit of a loss as to why suspend was suddenly broken.

I ended up finding the solution to the suspend problem while looking for a the solution to the Xorg 1.8 issues. This bug report proposed setting i915.powersave=0 on the kernel line in grub’s menu.lst file. This worked for me and I can now suspend again. In the bug report not everyone is claiming success with this solution.

Xorg 1.8 and video-intel 2.12.0 are giving many people issues: screen not redrawing properly, GPU hangs and slow 3D performance. I have not experienced the GPU hangs but that could be because I haven’t had my computer running long enough with the 2.12.0 driver for it to happen.

Another ArchLinux bug has the solution to the screen redraw issue. I followed Alyssa Hung (Deciare) instructions and applied this patch to Mesa 7.8.2. Installing the intel-dri package based on a patched Mesa made the screen redraw issues disappear completely.

I also found a possible fix for the GPU hang issue. Applying this patch to the kernel is supposed to work. I have not tried it myself.

As for the slow 3D performance, I have not found a fix. Short of disabling compositing simple tasks like changing virtual desktops and cycling though open windows is noticeably slower with 2.12.0. On my laptop (2.0 GHz Core 2 Duo) it is so slow that the animation stutters. This is not caused by the new drivers fixing the 3D frame rate to the vsync refresh rate because the frame rate is much lower than the vsyc rate. Until a fix is found for this problem I’ve reverted to using Xort 1.7 and video-intel 2.10.0.

Tags: intel, kernel, video, xorg