Created attachment 105601 [details] netconsole log of kernel panic I get a kernel panic most but not all of the time that the i915 module gets loaded. When it does load successfully, the system behaves normally. I'm using Arch Linux on an older MacBook (2,1) and have had the problem with all the 3.9 kernels I've tried thus far (3.9.3, 3.9.5, and 3.9.6). The problem does not occur with any of the 3.8 kernels I've used (3.8.4, 3.8.6, 3.8.8, 3.8.11) or any earlier kernel versions. Setting nomodeset on the kernel command line avoids the kernel panic. I tried modifying a number of the other i915 module parameters without any sort of consistent success. I've attached a netconsole log of one of the kernel panics.
Created attachment 105611 [details] output of lspci -s 00:02.0 -vv
Created attachment 105661 [details] Read the hardware state for the transcoder
Thanks. That patch seems to resolve the problem. Is it likely to make it into the mainline kernel soon?
Created attachment 105691 [details] modified version of the patch to patch cleanly against 3.9.6 Not sure if this is helpful, but figured I'd upload it in case it is.
Chris, the patch seems to have stalled at [1], will you pick it up? [1] http://mid.gmane.org/20130625124357.GS5823@phenom.ffwll.local
Daniel wants to completely rewrite the tested patch, so...
Created attachment 107156 [details] new patch which punts the pipe->cpu transcoder decoding to userspace
commit e8129b9113a71083a3eea13ae63b4bb848c47895 Author: Chris Wilson <chris@chris-wilson.co.uk> Date: Tue Jun 25 08:15:22 2013 +0100 drm/i915: Dump all transcoder registers on error Fix pushed to drm-intel-next-queued, please reopen if it doesn't work.
Patch needs more work, also it needs to go into -fixes with cc: stable.
Created attachment 107157 [details] don't deref the pipe->cpu_transcoder mapping in the hangcheck code Completely new patch, please test.
The new patch seems to work as well. I had to modify it slightly to patch cleanly against the 3.10.5 kernel sources (the current kernel for Arch Linux, the distribution I'm running). I'll upload the modified patch in case it's helpful.
Created attachment 107161 [details] modified version of new patch for 3.10.5
Fix merged with cc: stable, thanks for testing: commit 3d51af04567800a87a04785d375f1258977ef6d7 Author: Chris Wilson <chris@chris-wilson.co.uk> Date: Thu Aug 8 15:12:06 2013 +0200 drm/i915: Don't deref pipe->cpu_transcoder in the hangcheck code