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/aty/aty128fb.c b/drivers/video/aty/aty128fb.c
index 1fa211c..5d8f73b 100644
--- a/drivers/video/aty/aty128fb.c
+++ b/drivers/video/aty/aty128fb.c
@@ -1807,10 +1807,8 @@
mutex_lock(&info->bl_mutex);
if (info->bl_dev) {
- down(&info->bl_dev->sem);
info->bl_dev->props->power = power;
__aty128_bl_update_status(info->bl_dev);
- up(&info->bl_dev->sem);
}
mutex_unlock(&info->bl_mutex);
@@ -1847,11 +1845,9 @@
219 * FB_BACKLIGHT_MAX / MAX_LEVEL);
mutex_unlock(&info->bl_mutex);
- down(&bd->sem);
bd->props->brightness = aty128_bl_data.max_brightness;
bd->props->power = FB_BLANK_UNBLANK;
- bd->props->update_status(bd);
- up(&bd->sem);
+ backlight_update_status(bd);
#ifdef CONFIG_PMAC_BACKLIGHT
mutex_lock(&pmac_backlight_mutex);
diff --git a/drivers/video/aty/atyfb_base.c b/drivers/video/aty/atyfb_base.c
index 5ea5a00..23deb35 100644
--- a/drivers/video/aty/atyfb_base.c
+++ b/drivers/video/aty/atyfb_base.c
@@ -2188,10 +2188,8 @@
mutex_lock(&info->bl_mutex);
if (info->bl_dev) {
- down(&info->bl_dev->sem);
info->bl_dev->props->power = power;
__aty_bl_update_status(info->bl_dev);
- up(&info->bl_dev->sem);
}
mutex_unlock(&info->bl_mutex);
@@ -2224,11 +2222,9 @@
0xFF * FB_BACKLIGHT_MAX / MAX_LEVEL);
mutex_unlock(&info->bl_mutex);
- down(&bd->sem);
bd->props->brightness = aty_bl_data.max_brightness;
bd->props->power = FB_BLANK_UNBLANK;
- bd->props->update_status(bd);
- up(&bd->sem);
+ backlight_update_status(bd);
#ifdef CONFIG_PMAC_BACKLIGHT
mutex_lock(&pmac_backlight_mutex);
diff --git a/drivers/video/aty/radeon_backlight.c b/drivers/video/aty/radeon_backlight.c
index 8b66df6..9cfceca 100644
--- a/drivers/video/aty/radeon_backlight.c
+++ b/drivers/video/aty/radeon_backlight.c
@@ -194,11 +194,9 @@
217 * FB_BACKLIGHT_MAX / MAX_RADEON_LEVEL);
mutex_unlock(&rinfo->info->bl_mutex);
- down(&bd->sem);
bd->props->brightness = radeon_bl_data.max_brightness;
bd->props->power = FB_BLANK_UNBLANK;
- bd->props->update_status(bd);
- up(&bd->sem);
+ backlight_update_status(bd);
#ifdef CONFIG_PMAC_BACKLIGHT
mutex_lock(&pmac_backlight_mutex);
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
index 7a85be4..347081d 100644
--- a/drivers/video/backlight/backlight.c
+++ b/drivers/video/backlight/backlight.c
@@ -37,8 +37,7 @@
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 @@
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 @@
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 @@
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));
diff --git a/drivers/video/backlight/lcd.c b/drivers/video/backlight/lcd.c
index 9590248..1e1e61a 100644
--- a/drivers/video/backlight/lcd.c
+++ b/drivers/video/backlight/lcd.c
@@ -198,6 +198,7 @@
return ERR_PTR(-ENOMEM);
init_MUTEX(&new_ld->sem);
+ mutex_init(&new_ld->update_lock);
new_ld->props = lp;
memset(&new_ld->class_dev, 0, sizeof(new_ld->class_dev));
new_ld->class_dev.class = &lcd_class;
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 */
diff --git a/drivers/video/nvidia/nv_backlight.c b/drivers/video/nvidia/nv_backlight.c
index 4254c09..f5e42d0 100644
--- a/drivers/video/nvidia/nv_backlight.c
+++ b/drivers/video/nvidia/nv_backlight.c
@@ -114,10 +114,8 @@
mutex_lock(&info->bl_mutex);
if (info->bl_dev) {
- down(&info->bl_dev->sem);
info->bl_dev->props->power = power;
__nvidia_bl_update_status(info->bl_dev);
- up(&info->bl_dev->sem);
}
mutex_unlock(&info->bl_mutex);
@@ -154,11 +152,9 @@
0x534 * FB_BACKLIGHT_MAX / MAX_LEVEL);
mutex_unlock(&info->bl_mutex);
- down(&bd->sem);
bd->props->brightness = nvidia_bl_data.max_brightness;
bd->props->power = FB_BLANK_UNBLANK;
- bd->props->update_status(bd);
- up(&bd->sem);
+ backlight_update_status(bd);
#ifdef CONFIG_PMAC_BACKLIGHT
mutex_lock(&pmac_backlight_mutex);
diff --git a/drivers/video/riva/fbdev.c b/drivers/video/riva/fbdev.c
index fd82571..b70d18f 100644
--- a/drivers/video/riva/fbdev.c
+++ b/drivers/video/riva/fbdev.c
@@ -357,10 +357,8 @@
mutex_lock(&info->bl_mutex);
if (info->bl_dev) {
- down(&info->bl_dev->sem);
info->bl_dev->props->power = power;
__riva_bl_update_status(info->bl_dev);
- up(&info->bl_dev->sem);
}
mutex_unlock(&info->bl_mutex);
@@ -397,11 +395,9 @@
FB_BACKLIGHT_MAX);
mutex_unlock(&info->bl_mutex);
- down(&bd->sem);
bd->props->brightness = riva_bl_data.max_brightness;
bd->props->power = FB_BLANK_UNBLANK;
- bd->props->update_status(bd);
- up(&bd->sem);
+ backlight_update_status(bd);
#ifdef CONFIG_PMAC_BACKLIGHT
mutex_lock(&pmac_backlight_mutex);