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| author | Hans de Goede <hdegoede@redhat.com> | 2015-12-22 21:09:48 +0300 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2016-01-01 05:14:51 +0300 |
| commit | 90b066b15eda028ed44299f01236f8576dd8551d (patch) | |
| tree | 31f5d270508137734424f5f1474d35bc86976df5 /drivers/acpi/acpi_video.c | |
| parent | 74bf8efb5fa6e958d2d7c7917b8bb672085ec0c6 (diff) | |
| download | linux-90b066b15eda028ed44299f01236f8576dd8551d.tar.xz | |
ACPI / video: Add a acpi_video_handles_brightness_key_presses() helper
Several drivers want to know if the acpi-video is generating key-presses
for brightness change hotkeys to avoid sending double key-events to
userspace for these. Currently these driver use this construct for this:
if (acpi_video_get_backlight_type() == acpi_backlight_vendor)
report_brightness_key_event();
This indirect way of detecting if acpi-video is active does not make the
code easier to understand, and in some cases it is wrong because just
because the preferred type != vendor does not mean that acpi-video is
actually listening for brightness events, e.g. there may be no acpi-video
bus on the system at all.
This commit adds a acpi_video_handles_brightness_key_presses() helper
function, making the code needing this functionality both easier to read
and more correct.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/acpi_video.c')
| -rw-r--r-- | drivers/acpi/acpi_video.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/acpi/acpi_video.c b/drivers/acpi/acpi_video.c index 3405f7a41e25..2a649f3edefb 100644 --- a/drivers/acpi/acpi_video.c +++ b/drivers/acpi/acpi_video.c @@ -2072,6 +2072,18 @@ void acpi_video_unregister_backlight(void) mutex_unlock(®ister_count_mutex); } +bool acpi_video_handles_brightness_key_presses(void) +{ + bool have_video_busses; + + mutex_lock(&video_list_lock); + have_video_busses = !list_empty(&video_bus_head); + mutex_unlock(&video_list_lock); + + return have_video_busses; +} +EXPORT_SYMBOL(acpi_video_handles_brightness_key_presses); + /* * This is kind of nasty. Hardware using Intel chipsets may require * the video opregion code to be run first in order to initialise |