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| author | Zhang Rui <rui.zhang@intel.com> | 2012-06-20 09:48:43 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-07-16 09:04:06 -0700 |
| commit | 4849c078f07f5eb93eff651d3a32cdd434f0787a (patch) | |
| tree | 3fe62e4fdce5e8c0bcec87333cd2a9f47c42f387 /drivers/acpi | |
| parent | a00d69ed0676b53e7e5c8d086d47a92f15b91e38 (diff) | |
| download | lwn-4849c078f07f5eb93eff651d3a32cdd434f0787a.tar.gz lwn-4849c078f07f5eb93eff651d3a32cdd434f0787a.zip | |
ACPI video: Still use ACPI backlight control if _DOS doesn't exist
commit b03738430c7537d5f87948e0b35d8aaf2688c6b4 upstream.
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>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/video.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c index 66e8f7333e9b..48b5a3cda379 100644 --- a/drivers/acpi/video.c +++ b/drivers/acpi/video.c @@ -558,6 +558,8 @@ acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag) union acpi_object arg0 = { ACPI_TYPE_INTEGER }; struct acpi_object_list args = { 1, &arg0 }; + if (!video->cap._DOS) + return 0; if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1) return -EINVAL; |