[PATCH] powermac: Combined fixes for backlight code

This patch fixes several problems:
- pmac_backlight_key() is called under interrupt context, and therefore
  can't use mutexes or semaphores, so defer the backlight level for
  later, as it's not critical (original code by Aristeu S. Rozanski F.
  <aris@valeta.org>).
- Add exports for functions that might be called from modules
- Fix Kconfig depdencies on PMAC_BACKLIGHT.
- Fix locking issues on calls from inside the driver (reported by
  Aristeu S. Rozanski F., too)
- Fix wrong calculation of backlight values in some of the drivers
- Replace pmac_backlight_key_up/down by inline functions

[akpm@osdl.org: fix function prototypes]
Signed-off-by: Michael Hanselmann <linux-kernel@hansmi.ch>
Acked-by: Aristeu S. Rozanski F. <aris@valeta.org>
Acked-by: Rene Nussbaumer <linux-kernel@killerfox.forkbomb.ch>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 35 insertions, 31 deletions

diff --git a/drivers/video/aty/aty128fb.c b/drivers/video/aty/aty128fb.c
index 1006f125fcc7..c64a717e2d4b 100644
--- a/drivers/video/aty/aty128fb.c
+++ b/drivers/video/aty/aty128fb.c
@@ -455,6 +455,7 @@ static void do_wait_for_fifo(u16 entries, struct aty128fb_par *par);
 static void wait_for_fifo(u16 entries, struct aty128fb_par *par);
 static void wait_for_idle(struct aty128fb_par *par);
 static u32 depth_to_dst(u32 depth);
+static void aty128_bl_set_power(struct fb_info *info, int power);
 
 #define BIOS_IN8(v)     (readb(bios + (v)))
 #define BIOS_IN16(v)    (readb(bios + (v)) | \
@@ -1257,25 +1258,11 @@ static void aty128_set_lcd_enable(struct aty128fb_par *par, int on)
                 reg &= ~LVDS_DISPLAY_DIS;
                 aty_st_le32(LVDS_GEN_CNTL, reg);
 #ifdef CONFIG_FB_ATY128_BACKLIGHT
-                mutex_lock(&info->bl_mutex);
-                if (info->bl_dev) {
-                        down(&info->bl_dev->sem);
-                        info->bl_dev->props->update_status(info->bl_dev);
-                        up(&info->bl_dev->sem);
-                }
-                mutex_unlock(&info->bl_mutex);
+                aty128_bl_set_power(info, FB_BLANK_UNBLANK);
 #endif  
         } else {
 #ifdef CONFIG_FB_ATY128_BACKLIGHT
-                mutex_lock(&info->bl_mutex);
-                if (info->bl_dev) {
-                        down(&info->bl_dev->sem);
-                        info->bl_dev->props->brightness = 0;
-                        info->bl_dev->props->power = FB_BLANK_POWERDOWN;
-                        info->bl_dev->props->update_status(info->bl_dev);
-                        up(&info->bl_dev->sem);
-                }
-                mutex_unlock(&info->bl_mutex);
+                aty128_bl_set_power(info, FB_BLANK_POWERDOWN);
 #endif  
                 reg = aty_ld_le32(LVDS_GEN_CNTL);
                 reg |= LVDS_DISPLAY_DIS;
@@ -1702,6 +1689,7 @@ static int __devinit aty128fb_setup(char *options)
 
 static struct backlight_properties aty128_bl_data;
 
+/* Call with fb_info->bl_mutex held */
 static int aty128_bl_get_level_brightness(struct aty128fb_par *par,
                 int level)
 {
@@ -1709,10 +1697,8 @@ static int aty128_bl_get_level_brightness(struct aty128fb_par *par,
         int atylevel;
 
         /* Get and convert the value */
-        mutex_lock(&info->bl_mutex);
         atylevel = MAX_LEVEL -
                 (info->bl_curve[level] * FB_BACKLIGHT_MAX / MAX_LEVEL);
-        mutex_unlock(&info->bl_mutex);
 
         if (atylevel < 0)
                 atylevel = 0;
@@ -1730,7 +1716,8 @@ static int aty128_bl_get_level_brightness(struct aty128fb_par *par,
 /* That one prevents proper CRT output with LCD off */
 #undef BACKLIGHT_DAC_OFF
 
-static int aty128_bl_update_status(struct backlight_device *bd)
+/* Call with fb_info->bl_mutex held */
+static int __aty128_bl_update_status(struct backlight_device *bd)
 {
         struct aty128fb_par *par = class_get_devdata(&bd->class_dev);
         unsigned int reg = aty_ld_le32(LVDS_GEN_CNTL);
@@ -1783,6 +1770,19 @@ static int aty128_bl_update_status(struct backlight_device *bd)
         return 0;
 }
 
+static int aty128_bl_update_status(struct backlight_device *bd)
+{
+        struct aty128fb_par *par = class_get_devdata(&bd->class_dev);
+        struct fb_info *info = pci_get_drvdata(par->pdev);
+        int ret;
+
+        mutex_lock(&info->bl_mutex);
+        ret = __aty128_bl_update_status(bd);
+        mutex_unlock(&info->bl_mutex);
+
+        return ret;
+}
+
 static int aty128_bl_get_brightness(struct backlight_device *bd)
 {
         return bd->props->brightness;
@@ -1795,6 +1795,16 @@ static struct backlight_properties aty128_bl_data = {
         .max_brightness = (FB_BACKLIGHT_LEVELS - 1),
 };
 
+static void aty128_bl_set_power(struct fb_info *info, int power)
+{
+        mutex_lock(&info->bl_mutex);
+        up(&info->bl_dev->sem);
+        info->bl_dev->props->power = power;
+        __aty128_bl_update_status(info->bl_dev);
+        down(&info->bl_dev->sem);
+        mutex_unlock(&info->bl_mutex);
+}
+
 static void aty128_bl_init(struct aty128fb_par *par)
 {
         struct fb_info *info = pci_get_drvdata(par->pdev);
@@ -2197,12 +2207,8 @@ static int aty128fb_blank(int blank, struct fb_info *fb)
                 return 0;
 
 #ifdef CONFIG_FB_ATY128_BACKLIGHT
-        if (machine_is(powermac) && blank) {
-                down(&fb->bl_dev->sem);
-                fb->bl_dev->props->power = FB_BLANK_POWERDOWN;
-                fb->bl_dev->props->update_status(fb->bl_dev);
-                up(&fb->bl_dev->sem);
-        }
+        if (machine_is(powermac) && blank)
+                aty128_bl_set_power(fb, FB_BLANK_POWERDOWN);
 #endif
 
         if (blank & FB_BLANK_VSYNC_SUSPEND)
@@ -2218,14 +2224,12 @@ static int aty128fb_blank(int blank, struct fb_info *fb)
                 aty128_set_crt_enable(par, par->crt_on && !blank);
                 aty128_set_lcd_enable(par, par->lcd_on && !blank);
         }
+
 #ifdef CONFIG_FB_ATY128_BACKLIGHT
-        if (machine_is(powermac) && !blank) {
-                down(&fb->bl_dev->sem);
-                fb->bl_dev->props->power = FB_BLANK_UNBLANK;
-                fb->bl_dev->props->update_status(fb->bl_dev);
-                up(&fb->bl_dev->sem);
-        }
+        if (machine_is(powermac) && !blank)
+                aty128_bl_set_power(fb, FB_BLANK_UNBLANK);
 #endif
+
         return 0;
 }