tree d7074d96318895062cc0bba363e4e843ff5ab560
parent f8798ccbefc0e4ef7438c080b7ba0410738c8cfa
author Wolfram Stering <wolfram.stering@hale.at> 1316779775 +0200
committer Florian Tobias Schandinat <FlorianSchandinat@gmx.de> 1317657152 +0000

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>