Disabling polling in drm_helper

[Mike Verstegen]

> -----Original Message-----
> From: Daniel Vetter [mailto:daniel.vetter at ffwll.ch] On Behalf Of Daniel Vetter
> On Tue, Apr 23, 2013 at 01:16:16AM +0000, Mike Verstegen wrote:
> > I'm troubleshooting an interesting problem where the
> > i915_hotplug_work_func is eating up a lot of time in a couple of
> > kworker threads. The interesting part of the problem is that this only
> > happens with one particular model of monitor which I haven't gotten to
> > the bottom of yet. But that's not the problem I'm trying  to resolve.
> 
> This should be fixed in latest drm-next. Can you please test that?
> 
I'd be glad to test, but that may be a bit over my skill level.  How could I help with testing drm-next?
In my original message, I forgot to include that this is a Centos 6.4 system with a 3.5.3 kernel.

> > One band-aid for this trouble is to disable the polling in the
> > irq_event # echo "N" > /sys/module/drm_kms_helper/parameters/poll
> >
> > That quiets down the kworker threads. Good
> >
> > To make this survive across boots, I added the following to
> > /etc/modprobe/local.conf options drm_kms_helper poll=N
> >
> > On reboot, the poll is still enabled
> > [root at localhost ~]# cat /sys/module/drm_kms_helper/parameters/poll
> > Y
> > Questions:
> > - Am I using "options drm_kms_helper poll=N" correctly
> > - Is there a better way to have this option set to false on initialization?
> 
> You probably need to rebuild your initrd with your distro tools since
> drm_kms_helper is loaded really early.

Great suggestion and a good learning point for me. I rebuilt the initramfs and the option is now recognized at boot.

Thanks

Mike