[Bug 48932] i915_wait_irq error: system hangs while running heavy graphics applications

[Stephen Irons]

Public bug reported:

While running Celestia, Flightgear and TORCS, my system occasionally
hangs. The sound stop, mouse and keyboard freeze and the bottom section
of the display goes stripey.

After a few seconds, the screen goes blank and the X server cross-shaped
cursor appears, shortly before the Ubuntu rotating disk 'wait' cursor.
It looks as though GDM is trying to restart. However, the keyboard and
mouse are still frozen. It is not possible to activate a virtual
terminal using the keyboard.

The system does still respond to the power key and turns off after a few
seconds.

After restarting, syslog reports the following:

Jun  2 20:33:52 localhost -- MARK --
Jun  2 20:53:52 localhost -- MARK --
Jun  2 21:01:48 localhost kernel: [4297572.942000] [drm:i915_wait_irq] *ERROR* i915_wait_irq: EBUSY -- rec: 413596 emitted: 413599
Jun  2 21:01:52 localhost gdm[4894]: Error reinitilizing server
Jun  2 21:01:53 localhost shutdown[8424]: shutting down for system halt
Jun  2 21:02:37 localhost syslogd 1.4.1#17ubuntu7: restart.

Looking at a number of these reports, there is no consistency between
what is logged just before the *ERROR* i915_wait_irq message. The time
of the previous message is also variable: between 15 seconds and 3.5
minutes.

Hardware:
Dell Inspiron 6400
Core Duo 1.6 GHz
1G RAM
Intel 945GM integrated graphics

Software:
Ubuntu Dapper installed from Beta 2 install (now called alternate) CD and updated to final alternate CD and archives on 2006-06-01.
Kernel: 2.6.15-23-696-smp
xserver-xorg-driver-i810: 1:1.4.1.3-0ubuntu6
915resolution: 0.5-1ubuntu6

While running, RAM is sitting at about 400M occupied. According to the
CPU meters, one CPU is ticking over at 1GHz, the other at full speed
(1.6GHz). According to system monitor application, this CPU is about 80%
loaded, but the update rate is slow so I have no idea what the loading
is like in the last few seconds before the crash.

The crash occurs even when there are no other application open; however,
I have not yet tried to reduce the number of daemons.

** Affects: linux-source-2.6.15 (Ubuntu)
     Importance: Untriaged
         Status: Unconfirmed

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i915_wait_irq error: system hangs while running heavy graphics applications
https://launchpad.net/bugs/48932