[POWERPC] Fix sleep on some powerbooks

The PMU backlight code would kick in during sleep/resume even on
machines that use a different backlight method.  This breaks
sleep on some PowerBooks.

This fixes it by adding a flag to indicate whether the backlight
is controlled by the PMU, and testing that before trying to use
the PMU to turn off the backlight during sleep.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/drivers/macintosh/via-pmu-backlight.c b/drivers/macintosh/via-pmu-backlight.c
index 741a2e3f4fc6..a348bb0791d3 100644
--- a/drivers/macintosh/via-pmu-backlight.c
+++ b/drivers/macintosh/via-pmu-backlight.c
@@ -17,7 +17,7 @@
 
 static struct backlight_ops pmu_backlight_data;
 static DEFINE_SPINLOCK(pmu_backlight_lock);
-static int sleeping;
+static int sleeping, uses_pmu_bl;
 static u8 bl_curve[FB_BACKLIGHT_LEVELS];
 
 static void pmu_backlight_init_curve(u8 off, u8 min, u8 max)
@@ -128,7 +128,7 @@ void pmu_backlight_set_sleep(int sleep)
 
         spin_lock_irqsave(&pmu_backlight_lock, flags);
         sleeping = sleep;
-        if (pmac_backlight) {
+        if (pmac_backlight && uses_pmu_bl) {
                 if (sleep) {
                         struct adb_request req;
 
@@ -166,6 +166,7 @@ void __init pmu_backlight_init()
                 printk(KERN_ERR "PMU Backlight registration failed\n");
                 return;
         }
+        uses_pmu_bl = 1;
         bd->props.max_brightness = FB_BACKLIGHT_LEVELS - 1;
         pmu_backlight_init_curve(0x7F, 0x46, 0x0E);