On Wed, 29 Sep 2010 11:36:22 +0200, Toralf Förster toralf.foerster@gmx.de wrote:
Hello,
today I run at the latest 2.6.35.6 kernel few apps like Lotus Notes under wine, amarok and firefox and in parallel a "git bisect" when I got this :
n22 ~ # grep 2010-09-29T11:21 /var/log/messages | grep kernel 2010-09-29T11:21:36.984+02:00 n22 kernel: INFO: task i915:868 blocked for more than 120 seconds. 2010-09-29T11:21:36.984+02:00 n22 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 2010-09-29T11:21:36.984+02:00 n22 kernel: i915 D ffa47280 0 868 2 0x00000000
It's a mysterious lost interrupt (or a touch of incoherency around the dword seqno write). The pipe control dance is meant to ensure the write to memory is truly flushed before the interrupt fires. [T400 is ironlake?]
cat /sys/kernel/debug/dri/0/i915_gem_interrupt
That should show whether the seqno was ever updated. We could extend that file by recording the number of User Interrupts since waiting to see if we miss the interrupt.
drm-intel-next contains patches to hopefully workaround the hang. So hopefully your machine will no longer die whilst we uncover the root cause. -Chris