Merge branch 'for-linus' of git://git.o-hand.com/linux-rpurdie-backlight

* 'for-linus' of git://git.o-hand.com/linux-rpurdie-backlight:
  backlight: Remove bogus SYSFS dependency
  backlight: simplify corgi_bl locking
  backlight: Separate backlight properties from backlight ops pointers
  backlight: Clean up pmac_backlight handling
  backlight: Improve backlight selection for fbdev drivers
  backlight: Rework backlight/fb interaction simplifying, lots
  backlight: Remove unneeded backlight update_status calls
  backlight: Remove uneeded update_status call from chipsfb.c
  backlight/fbcon: Add FB_EVENT_CONBLANK
  backlight: Fix Kconfig entries
  backlight: Remove uneeded nvidia set_power calls
  backlight: Convert semaphore -> mutex
  backlight: Fix external uses of backlight internal semaphore
  backlight: Minor code cleanups for hp680_bl.c
  backlight: Minor code cleanups for corgi_bl.c
  backlight: Remove excessive (un)likelys
  backlight: Remove unneeded owner field
  backlight: Fix error handling
  backlight: Add Frontpath ProGear HX1050+ driver
  backlight: Add maintainer entry

2 files changed, 11 insertions, 22 deletions

diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index dcc6f159fd94..17724fb2067f 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -107,12 +107,10 @@ int die(const char *str, struct pt_regs *regs, long err)
         if (machine_is(powermac) && pmac_backlight) {
                 struct backlight_properties *props;
 
-                down(&pmac_backlight->sem);
-                props = pmac_backlight->props;
+                props = &pmac_backlight->props;
                 props->brightness = props->max_brightness;
                 props->power = FB_BLANK_UNBLANK;
-                props->update_status(pmac_backlight);
-                up(&pmac_backlight->sem);
+                backlight_update_status(pmac_backlight);
         }
         mutex_unlock(&pmac_backlight_mutex);
 #endif
diff --git a/arch/powerpc/platforms/powermac/backlight.c b/arch/powerpc/platforms/powermac/backlight.c
index c3a89414ddc0..de7440e62cc4 100644
--- a/arch/powerpc/platforms/powermac/backlight.c
+++ b/arch/powerpc/platforms/powermac/backlight.c
@@ -37,21 +37,20 @@ static int pmac_backlight_set_legacy_queued;
  */
 static atomic_t kernel_backlight_disabled = ATOMIC_INIT(0);
 
-/* Protect the pmac_backlight variable */
+/* Protect the pmac_backlight variable below.
+   You should hold this lock when using the pmac_backlight pointer to
+   prevent its potential removal. */
 DEFINE_MUTEX(pmac_backlight_mutex);
 
 /* Main backlight storage
  *
- * Backlight drivers in this variable are required to have the "props"
+ * Backlight drivers in this variable are required to have the "ops"
  * attribute set and to have an update_status function.
  *
  * We can only store one backlight here, but since Apple laptops have only one
  * internal display, it doesn't matter. Other backlight drivers can be used
  * independently.
  *
- * Lock ordering:
- * pmac_backlight_mutex (global, main backlight)
- *   pmac_backlight->sem (backlight class)
  */
 struct backlight_device *pmac_backlight;
 
@@ -104,8 +103,7 @@ static void pmac_backlight_key_worker(struct work_struct *work)
                 struct backlight_properties *props;
                 int brightness;
 
-                down(&pmac_backlight->sem);
-                props = pmac_backlight->props;
+                props = &pmac_backlight->props;
 
                 brightness = props->brightness +
                         ((pmac_backlight_key_queued?-1:1) *
@@ -117,9 +115,7 @@ static void pmac_backlight_key_worker(struct work_struct *work)
                         brightness = props->max_brightness;
 
                 props->brightness = brightness;
-                props->update_status(pmac_backlight);
-
-                up(&pmac_backlight->sem);
+                backlight_update_status(pmac_backlight);
         }
         mutex_unlock(&pmac_backlight_mutex);
 }
@@ -145,8 +141,7 @@ static int __pmac_backlight_set_legacy_brightness(int brightness)
         if (pmac_backlight) {
                 struct backlight_properties *props;
 
-                down(&pmac_backlight->sem);
-                props = pmac_backlight->props;
+                props = &pmac_backlight->props;
                 props->brightness = brightness *
                         (props->max_brightness + 1) /
                         (OLD_BACKLIGHT_MAX + 1);
@@ -156,8 +151,7 @@ static int __pmac_backlight_set_legacy_brightness(int brightness)
                 else if (props->brightness < 0)
                         props->brightness = 0;
 
-                props->update_status(pmac_backlight);
-                up(&pmac_backlight->sem);
+                backlight_update_status(pmac_backlight);
 
                 error = 0;
         }
@@ -196,14 +190,11 @@ int pmac_backlight_get_legacy_brightness()
         if (pmac_backlight) {
                 struct backlight_properties *props;
 
-                down(&pmac_backlight->sem);
-                props = pmac_backlight->props;
+                props = &pmac_backlight->props;
 
                 result = props->brightness *
                         (OLD_BACKLIGHT_MAX + 1) /
                         (props->max_brightness + 1);
-
-                up(&pmac_backlight->sem);
         }
         mutex_unlock(&pmac_backlight_mutex);