[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, 30 insertions, 23 deletions

diff --git a/drivers/video/aty/atyfb_base.c b/drivers/video/aty/atyfb_base.c
index 0c9706746d79..1507d19f481f 100644
--- a/drivers/video/aty/atyfb_base.c
+++ b/drivers/video/aty/atyfb_base.c
@@ -2129,15 +2129,14 @@ static int atyfb_pci_resume(struct pci_dev *pdev)
 
 static struct backlight_properties aty_bl_data;
 
+/* Call with fb_info->bl_mutex held */
 static int aty_bl_get_level_brightness(struct atyfb_par *par, int level)
 {
         struct fb_info *info = pci_get_drvdata(par->pdev);
         int atylevel;
 
         /* Get and convert the value */
-        mutex_lock(&info->bl_mutex);
         atylevel = info->bl_curve[level] * FB_BACKLIGHT_MAX / MAX_LEVEL;
-        mutex_unlock(&info->bl_mutex);
 
         if (atylevel < 0)
                 atylevel = 0;
@@ -2147,7 +2146,8 @@ static int aty_bl_get_level_brightness(struct atyfb_par *par, int level)
         return atylevel;
 }
 
-static int aty_bl_update_status(struct backlight_device *bd)
+/* Call with fb_info->bl_mutex held */
+static int __aty_bl_update_status(struct backlight_device *bd)
 {
         struct atyfb_par *par = class_get_devdata(&bd->class_dev);
         unsigned int reg = aty_ld_lcd(LCD_MISC_CNTL, par);
@@ -2172,6 +2172,19 @@ static int aty_bl_update_status(struct backlight_device *bd)
         return 0;
 }
 
+static int aty_bl_update_status(struct backlight_device *bd)
+{
+        struct atyfb_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 = __aty_bl_update_status(bd);
+        mutex_unlock(&info->bl_mutex);
+
+        return ret;
+}
+
 static int aty_bl_get_brightness(struct backlight_device *bd)
 {
         return bd->props->brightness;
@@ -2184,6 +2197,16 @@ static struct backlight_properties aty_bl_data = {
         .max_brightness = (FB_BACKLIGHT_LEVELS - 1),
 };
 
+static void aty_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;
+        __aty_bl_update_status(info->bl_dev);
+        down(&info->bl_dev->sem);
+        mutex_unlock(&info->bl_mutex);
+}
+
 static void aty_bl_init(struct atyfb_par *par)
 {
         struct fb_info *info = pci_get_drvdata(par->pdev);
@@ -2790,16 +2813,8 @@ static int atyfb_blank(int blank, struct fb_info *info)
                 return 0;
 
 #ifdef CONFIG_PMAC_BACKLIGHT
-        if (machine_is(powermac) && blank > FB_BLANK_NORMAL) {
-                mutex_lock(&info->bl_mutex);
-                if (info->bl_dev) {
-                        down(&info->bl_dev->sem);
-                        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);
-        }
+        if (machine_is(powermac) && blank > FB_BLANK_NORMAL)
+                aty_bl_set_power(info, FB_BLANK_POWERDOWN);
 #elif defined(CONFIG_FB_ATY_GENERIC_LCD)
         if (par->lcd_table && blank > FB_BLANK_NORMAL &&
             (aty_ld_lcd(LCD_GEN_CNTL, par) & LCD_ON)) {
@@ -2830,16 +2845,8 @@ static int atyfb_blank(int blank, struct fb_info *info)
         aty_st_le32(CRTC_GEN_CNTL, gen_cntl, par);
 
 #ifdef CONFIG_PMAC_BACKLIGHT
-        if (machine_is(powermac) && blank <= FB_BLANK_NORMAL) {
-                mutex_lock(&info->bl_mutex);
-                if (info->bl_dev) {
-                        down(&info->bl_dev->sem);
-                        info->bl_dev->props->power = FB_BLANK_UNBLANK;
-                        info->bl_dev->props->update_status(info->bl_dev);
-                        up(&info->bl_dev->sem);
-                }
-                mutex_unlock(&info->bl_mutex);
-        }
+        if (machine_is(powermac) && blank <= FB_BLANK_NORMAL)
+                aty_bl_set_power(info, FB_BLANK_UNBLANK);
 #elif defined(CONFIG_FB_ATY_GENERIC_LCD)
         if (par->lcd_table && blank <= FB_BLANK_NORMAL &&
             (aty_ld_lcd(LCD_GEN_CNTL, par) & LCD_ON)) {