[Intel-gfx] i915: hotplug events gone wild

[Andrew Lutomirski]

On Sat, Jan 30, 2010 at 10:02 PM, Andrew Lutomirski <luto at mit.edu> wrote:
> [I posted this bug earlier with a terrible description as "resume
> lagginess and other problems."  Here it is again with a better bug
> report.]
>
> I'm running 2.6.33-rc5 (plus some wireless-testing stuff, but I've
> seen this problem on a variety of 2.6.33-rc? kernels).  Every now and
> then, X starts to lag badly on my GM45 laptop.  When this happens, I
> usually see a bunch of events in udevmonitor.  Running with
> drm.debug=0x02 (and the patch below to keep the log under control), I
> see tons of messages like this:

I triggered it again.  This time, the messages looked like
(drm.debug=3 from a different VT to avoid all the hotplug stuff
running off the screen, and running a different debugging hack -- see
all the way at the bottom):

[ 1324.285057] [drm:i915_driver_irq_handler], hotplug event received,
stat 0x28200000, mask 0x38000800
[ 1324.285086] [drm:i915_hotplug_work_func], i915_hotplug_work_func
[ 1324.285093] [drm:drm_sysfs_hotplug_event], generating hotplug event
[ 1324.290356] [drm:i915_driver_irq_handler], hotplug event received,
stat 0x28200000, mask 0x38000800
[ 1324.290388] [drm:i915_hotplug_work_func], i915_hotplug_work_func
[ 1324.290395] [drm:drm_sysfs_hotplug_event], generating hotplug event
[ 1324.296512] [drm:i915_driver_irq_handler], hotplug event received,
stat 0x28200000, mask 0x38000800
[ 1324.296536] [drm:i915_hotplug_work_func], i915_hotplug_work_func
[ 1324.296543] [drm:drm_sysfs_hotplug_event], generating hotplug event
[ 1324.307078] [drm:i915_driver_irq_handler], hotplug event received,
stat 0x20200000, mask 0x38000800
[ 1324.307104] [drm:i915_hotplug_work_func], i915_hotplug_work_func
[ 1324.307111] [drm:drm_sysfs_hotplug_event], generating hotplug event