backlight: Fix external uses of backlight internal semaphore
backlight_device->sem has a very specific use as documented in the
header file. The external users of this are using it for a different
reason, to serialise access to the update_status() method.
backlight users were supposed to implement their own internal
serialisation of update_status() if needed but everyone is doing
things differently and incorrectly. Therefore add a global mutex to
take care of serialisation for everyone, once and for all.
Locking for get_brightness remains optional since most users don't
need it.
Also update the lcd class in a similar way.
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
diff --git a/drivers/misc/asus-laptop.c b/drivers/misc/asus-laptop.c
index d15ee5e..7ace5b9a 100644
--- a/drivers/misc/asus-laptop.c
+++ b/drivers/misc/asus-laptop.c
@@ -348,13 +348,8 @@
struct backlight_device *bd = asus_backlight_device;
if (bd) {
- down(&bd->sem);
- if (likely(bd->props)) {
- bd->props->power = blank;
- if (likely(bd->props->update_status))
- bd->props->update_status(bd);
- }
- up(&bd->sem);
+ bd->props->power = blank;
+ backlight_update_status(bd);
}
}
@@ -1028,14 +1023,9 @@
asus_backlight_device = bd;
- down(&bd->sem);
- if (likely(bd->props)) {
- bd->props->brightness = read_brightness(NULL);
- bd->props->power = FB_BLANK_UNBLANK;
- if (likely(bd->props->update_status))
- bd->props->update_status(bd);
- }
- up(&bd->sem);
+ bd->props->brightness = read_brightness(NULL);
+ bd->props->power = FB_BLANK_UNBLANK;
+ backlight_update_status(bd);
}
return 0;
}