The M3800 is very minor workstation variant of the XPS 15 which has
already been patched for this issue.  I figured it's probably more
important for this version of the laptop to be patched than the
regular XPS as Dell sells is pre-configured with Ubuntu to be used as
a Linux workstation.  I have tested the patch on my the hardware on
Linux 4.2.0.
Signed-off-by: Niranjan Sivakumar <ns253@cornell.edu>
Cc: <stable@vger.kernel.org> # v4.1+
Signed-off-by: Takashi Iwai <tiwai@suse.de>