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authorRichard Purdie <rpurdie@rpsys.net>2007-02-08 22:25:09 +0000
committerRichard Purdie <rpurdie@rpsys.net>2007-02-20 08:38:45 +0000
commit28ee086d5b36aab2931f6740e409bb0fb6c65e5f (patch)
tree0a308c80affcc39c2c869f29f1109e5ee9d6140f /drivers/video/backlight/backlight.c
parenta8db3c1948eb30cd6988b5b96b654f591e6280b1 (diff)
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>
Diffstat (limited to 'drivers/video/backlight/backlight.c')
-rw-r--r--drivers/video/backlight/backlight.c10
1 files changed, 4 insertions, 6 deletions
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
index 7a85be4d2b0..347081daf7a 100644
--- a/drivers/video/backlight/backlight.c
+++ b/drivers/video/backlight/backlight.c
@@ -37,8 +37,7 @@ static int fb_notifier_callback(struct notifier_block *self,
if (!bd->props->check_fb ||
bd->props->check_fb(evdata->info)) {
bd->props->fb_blank = *(int *)evdata->data;
- if (bd->props && bd->props->update_status)
- bd->props->update_status(bd);
+ backlight_update_status(bd);
}
up(&bd->sem);
return 0;
@@ -97,8 +96,7 @@ static ssize_t backlight_store_power(struct class_device *cdev, const char *buf,
if (bd->props) {
pr_debug("backlight: set power to %d\n", power);
bd->props->power = power;
- if (bd->props->update_status)
- bd->props->update_status(bd);
+ backlight_update_status(bd);
rc = count;
}
up(&bd->sem);
@@ -140,8 +138,7 @@ static ssize_t backlight_store_brightness(struct class_device *cdev, const char
pr_debug("backlight: set brightness to %d\n",
brightness);
bd->props->brightness = brightness;
- if (bd->props->update_status)
- bd->props->update_status(bd);
+ backlight_update_status(bd);
rc = count;
}
}
@@ -230,6 +227,7 @@ struct backlight_device *backlight_device_register(const char *name,
if (!new_bd)
return ERR_PTR(-ENOMEM);
+ mutex_init(&new_bd->update_lock);
init_MUTEX(&new_bd->sem);
new_bd->props = bp;
memset(&new_bd->class_dev, 0, sizeof(new_bd->class_dev));