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| author | Aaron Lu <aaron.lu@intel.com> | 2014-09-30 14:10:17 +0800 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2014-09-30 20:49:19 +0200 |
| commit | 0b8db271f1592e118feef7300f6da85bea9366da (patch) | |
| tree | 1701b43f8b4b9a557719b753d04797917390085b /drivers/acpi/video.c | |
| parent | a11d342fb89aedec5003d116e7427d43cbba714d (diff) | |
| download | linux-0b8db271f1592e118feef7300f6da85bea9366da.tar.gz linux-0b8db271f1592e118feef7300f6da85bea9366da.tar.bz2 linux-0b8db271f1592e118feef7300f6da85bea9366da.zip | |
ACPI / video: check _DOD list when creating backlight devices
The _DOD method lists which video output device is currently attached so
we should only care about them and ignore others. An user recently
reported that there are two acpi_video interfaces appeared on his system
and one of them doesn't work. From the acpidump, it is found that there
are more than one video output devices that have _BCM control method but
the _DOD lists only one of them. So this patch checks if the video output
device is in the _DOD list and will not create backlight device if it is
not in the list. Also, we consider the broken _DOD case(reflected by the
video->attached_count is 0) and do not change behaviour for those broken
_DOD systems.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=84111
Reported-and-tested-by: ntrrgc@gmail.com
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/video.c')
| -rw-r--r-- | drivers/acpi/video.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c index 5a98e1db68c0..015b93df5201 100644 --- a/drivers/acpi/video.c +++ b/drivers/acpi/video.c @@ -1146,6 +1146,23 @@ acpi_video_device_bind(struct acpi_video_bus *video, } } +static bool acpi_video_device_in_dod(struct acpi_video_device *device) +{ + struct acpi_video_bus *video = device->video; + int i; + + /* If we have a broken _DOD, no need to test */ + if (!video->attached_count) + return true; + + for (i = 0; i < video->attached_count; i++) { + if (video->attached_array[i].bind_info == device) + return true; + } + + return false; +} + /* * Arg: * video : video bus device @@ -1585,6 +1602,15 @@ static void acpi_video_dev_register_backlight(struct acpi_video_device *device) static int count; char *name; + /* + * Do not create backlight device for video output + * device that is not in the enumerated list. + */ + if (!acpi_video_device_in_dod(device)) { + dev_dbg(&device->dev->dev, "not in _DOD list, ignore\n"); + return; + } + result = acpi_video_init_brightness(device); if (result) return; |