Commit 90b066b1 authored by Hans de Goede's avatar Hans de Goede Committed by Rafael J. Wysocki
Browse files

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: default avatarHans de Goede <hdegoede@redhat.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 74bf8efb

drivers/acpi/acpi_video.c

+12 −0
Original line number Diff line number Diff line
@@ -2072,6 +2072,18 @@ void acpi_video_unregister_backlight(void) 
	mutex_unlock(&register_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

include/acpi/video.h

+6 −0
Original line number Diff line number Diff line
@@ -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

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