[PATCH] powerpc: More via-pmu backlight fixes

The via-pmu backlight code (introduced in 2.6.18) has various design issues
causing crashes on machines using it like the old Wallstreet powerbook
(Michael, the author, never managed to test on these and I just got my hand
on one of those old beasts).

This fixes them by no longer trying to hijack the backlight device of the
frontmost framebuffer (causing that framebuffer to crash) but having it's
own local bits instead.  Might look weird but it's better that way on those
old machines, at least as a last-minute fix for 2.6.18.  We might rework
the whole thing later.  This patch also changes the way it gets notified of
sleep and wakeup in order to properly shut the backlight down on sleep and
bring it back on wakeup.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/macintosh/via-pmu.c b/drivers/macintosh/via-pmu.c
index ea386801e215..14610a63f580 100644
--- a/drivers/macintosh/via-pmu.c
+++ b/drivers/macintosh/via-pmu.c
@@ -1995,6 +1995,8 @@ restore_via_state(void)
         out_8(&via[IER], IER_SET | SR_INT | CB1_INT);
 }
 
+extern void pmu_backlight_set_sleep(int sleep);
+
 static int
 pmac_suspend_devices(void)
 {
@@ -2032,6 +2034,11 @@ pmac_suspend_devices(void)
                 return -EBUSY;
         }
 
+#ifdef CONFIG_PMAC_BACKLIGHT
+        /* Tell backlight code not to muck around with the chip anymore */
+        pmu_backlight_set_sleep(1);
+#endif
+
         /* Call platform functions marked "on sleep" */
         pmac_pfunc_i2c_suspend();
         pmac_pfunc_base_suspend();
@@ -2090,6 +2097,11 @@ pmac_wakeup_devices(void)
 {
         mdelay(100);
 
+#ifdef CONFIG_PMAC_BACKLIGHT
+        /* Tell backlight code it can use the chip again */
+        pmu_backlight_set_sleep(0);
+#endif
+
         /* Power back up system devices (including the PIC) */
         device_power_up();