tree 70dd0d5aa1e40118bf60c5c6642bbc8715768722
parent 76e10d158efb6d4516018846f60c2ab5501900bc
author Zhang Rui <rui.zhang@intel.com> 1340156923 +0800
committer Len Brown <len.brown@intel.com> 1341031422 -0400

ACPI video: Still use ACPI backlight control if _DOS doesn't exist

This fixes a regression in 3.4-rc1 caused by commit
ea9f8856bd6d4ed45885b06a338f7362cd6c60e5
(ACPI video: Harden video bus adding.)

Some platforms don't have _DOS control method, but the ACPI
backlight still works.
We should not invoke _DOS for these platforms.

https://bugzilla.kernel.org/show_bug.cgi?id=43168

Cc: Igor Murzov <intergalactic.anonymous@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>