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/video/chipsfb.c b/drivers/video/chipsfb.c
index 73cb426..9a656bc 100644
--- a/drivers/video/chipsfb.c
+++ b/drivers/video/chipsfb.c
@@ -153,13 +153,11 @@
* useful at blank = 1 too (saves battery, extends backlight
* life)
*/
- down(&pmac_backlight->sem);
if (blank)
pmac_backlight->props->power = FB_BLANK_POWERDOWN;
else
pmac_backlight->props->power = FB_BLANK_UNBLANK;
- pmac_backlight->props->update_status(pmac_backlight);
- up(&pmac_backlight->sem);
+ backlight_update_status(pmac_backlight);
}
mutex_unlock(&pmac_backlight_mutex);
@@ -415,10 +413,8 @@
/* turn on the backlight */
mutex_lock(&pmac_backlight_mutex);
if (pmac_backlight) {
- down(&pmac_backlight->sem);
pmac_backlight->props->power = FB_BLANK_UNBLANK;
- pmac_backlight->props->update_status(pmac_backlight);
- up(&pmac_backlight->sem);
+ backlight_update_status(pmac_backlight);
}
mutex_unlock(&pmac_backlight_mutex);
#endif /* CONFIG_PMAC_BACKLIGHT */