Comment 298 for bug 1140716

(In reply to comment #24)
> Mikhail, for the time being you can set i915.semaphores=0 (or echo 0 >
> /sys/modules/i915/parameters/semaphores) to prevent this hang.

What are the consequences?

> The only interesting patch I can suggest atm is
>
> commit 31643d54a739382626c27c0f2a12b3bbc22d1a38
> Author: Ben Widawsky <email address hidden>
> Date: Wed Sep 26 10:34:01 2012 -0700
>
> drm/i915: Workaround to bump rc6 voltage to 450
>
> BIOS should be setting the minimum voltage for rc6 to be 450mV. Old or
> buggy BIOSen may not be doing this, so we correct it for them. Ideally
> customers should update the BIOS as only it would know the optimal
> values for the platform, so we leave that fact as a DRM_ERROR for the
> user to see.
>
> in 3.8-rc1 or look for a BIOS update.

I have H61M/U3S3 motherboard and you latest BIOS ver 2.20 from 8/15/2012
ftp://174.142.97.10/bios/1155/H61MU3S3(2.20)ROM.zip
How to check problem persists or not?