Comment # 35 on bug 1219522 from Takashi Iwai

I'm asking it because my test patch is merely a workaround and for spotting out
the cause.  It has to be reported to the upstream devs and address more
properly.  That'll be the final fix.

If the bug is really about the NULL dereference there, the kernel warning
should appear, and it has to be verified.  Then we need to understand why this
NULL dereference happens at the first place.  My test kernel is provided for
checking that.

So, please upload the dmesg output from the test kernel.  Then please confirm
whether the touchpad is still actually enabled or not.  If the touchpad is
dead,  it might be a half-baked probe of touchpad that caused the problem.