mx3fb: fix NULL pointer dereference in screen blanking.
authorWolfram Stering <wolfram.stering@hale.at>
Fri, 23 Sep 2011 12:09:35 +0000 (14:09 +0200)
committerFlorian Tobias Schandinat <FlorianSchandinat@gmx.de>
Mon, 3 Oct 2011 15:52:32 +0000 (15:52 +0000)
commit8b53b7fb57e1ce3441b1a32f8374874b53c4bc31
treed7074d96318895062cc0bba363e4e843ff5ab560
parentf8798ccbefc0e4ef7438c080b7ba0410738c8cfa
mx3fb: fix NULL pointer dereference in screen blanking.

When blanking an already blanked framebuffer, a kernel NULL pointer
dereference occurred, because mx3fb driver handles all kinds of screen
blanking (normal, vsync suspend, powerdown) in the same way.
Certain programs (Xorg X11 server) first do a normal blank, followed by
a powerdown blank, which triggered the bug.

Add an additional safeguard and make sdc_disable_channel() safe against
multiple calls independent of other logic.

Signed-off-by: Michael Thalmeier <michael.thalmeier@hale.at>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
drivers/video/mx3fb.c