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@xxxxxxxxxx> --- drivers/acpi/acpi_video.c | 12 ++++++++++++ include/acpi/video.h | 6 ++++++ 2 files changed, 18 insertions(+) diff --git a/drivers/acpi/acpi_video.c b/drivers/acpi/acpi_video.c index 3405f7a..2a649f3e 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 diff --git a/include/acpi/video.h b/include/acpi/video.h index c62392d..f11d342 100644 --- a/include/acpi/video.h +++ b/include/acpi/video.h @@ -2,6 +2,7 @@ #define __ACPI_VIDEO_H #include <linux/errno.h> /* for ENODEV */ +#include <linux/types.h> /* for bool */ struct acpi_device; @@ -31,6 +32,7 @@ extern int acpi_video_get_edid(struct acpi_device *device, int type, int device_id, void **edid); extern enum acpi_backlight_type acpi_video_get_backlight_type(void); extern void acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type); +extern bool acpi_video_handles_brightness_key_presses(void); #else static inline int acpi_video_register(void) { return 0; } static inline void acpi_video_unregister(void) { return; } @@ -46,6 +48,10 @@ static inline enum acpi_backlight_type acpi_video_get_backlight_type(void) static inline void acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type) { } +static inline bool acpi_video_handles_brightness_key_presses(void) +{ + return false; +} #endif #endif -- 2.5.0 -- To unsubscribe from this list: send the line "unsubscribe platform-driver-x86" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html