[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>

7 files changed, 127 insertions, 84 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;
 }
 
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)) {
diff --git a/drivers/video/chipsfb.c b/drivers/video/chipsfb.c
index eba9d93ae360..73cb426bf2d7 100644
--- a/drivers/video/chipsfb.c
+++ b/drivers/video/chipsfb.c
@@ -149,12 +149,11 @@ static int chipsfb_blank(int blank, struct fb_info *info)
         mutex_lock(&pmac_backlight_mutex);
 
         if (pmac_backlight) {
-                down(&pmac_backlight->sem);
-
                 /* used to disable backlight only for blank > 1, but it seems
                  * useful at blank = 1 too (saves battery, extends backlight
                  * life)
                  */
+                down(&pmac_backlight->sem);
                 if (blank)
                         pmac_backlight->props->power = FB_BLANK_POWERDOWN;
                 else
diff --git a/drivers/video/nvidia/nv_backlight.c b/drivers/video/nvidia/nv_backlight.c
index 1c1c10c699c5..b45f577094ac 100644
--- a/drivers/video/nvidia/nv_backlight.c
+++ b/drivers/video/nvidia/nv_backlight.c
@@ -26,9 +26,11 @@
  */
 #define MIN_LEVEL 0x158
 #define MAX_LEVEL 0x534
+#define LEVEL_STEP ((MAX_LEVEL - MIN_LEVEL) / FB_BACKLIGHT_MAX)
 
 static struct backlight_properties nvidia_bl_data;
 
+/* Call with fb_info->bl_mutex held */
 static int nvidia_bl_get_level_brightness(struct nvidia_par *par,
                 int level)
 {
@@ -36,9 +38,7 @@ static int nvidia_bl_get_level_brightness(struct nvidia_par *par,
         int nlevel;
 
         /* Get and convert the value */
-        mutex_lock(&info->bl_mutex);
-        nlevel = info->bl_curve[level] * FB_BACKLIGHT_MAX / MAX_LEVEL;
-        mutex_unlock(&info->bl_mutex);
+        nlevel = MIN_LEVEL + info->bl_curve[level] * LEVEL_STEP;
 
         if (nlevel < 0)
                 nlevel = 0;
@@ -50,7 +50,8 @@ static int nvidia_bl_get_level_brightness(struct nvidia_par *par,
         return nlevel;
 }
 
-static int nvidia_bl_update_status(struct backlight_device *bd)
+/* Call with fb_info->bl_mutex held */
+static int __nvidia_bl_update_status(struct backlight_device *bd)
 {
         struct nvidia_par *par = class_get_devdata(&bd->class_dev);
         u32 tmp_pcrt, tmp_pmc, fpcontrol;
@@ -84,6 +85,19 @@ static int nvidia_bl_update_status(struct backlight_device *bd)
         return 0;
 }
 
+static int nvidia_bl_update_status(struct backlight_device *bd)
+{
+        struct nvidia_par *par = class_get_devdata(&bd->class_dev);
+        struct fb_info *info = pci_get_drvdata(par->pci_dev);
+        int ret;
+
+        mutex_lock(&info->bl_mutex);
+        ret = __nvidia_bl_update_status(bd);
+        mutex_unlock(&info->bl_mutex);
+
+        return ret;
+}
+
 static int nvidia_bl_get_brightness(struct backlight_device *bd)
 {
         return bd->props->brightness;
@@ -96,6 +110,16 @@ static struct backlight_properties nvidia_bl_data = {
         .max_brightness = (FB_BACKLIGHT_LEVELS - 1),
 };
 
+void nvidia_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;
+        __nvidia_bl_update_status(info->bl_dev);
+        down(&info->bl_dev->sem);
+        mutex_unlock(&info->bl_mutex);
+}
+
 void nvidia_bl_init(struct nvidia_par *par)
 {
         struct fb_info *info = pci_get_drvdata(par->pci_dev);
diff --git a/drivers/video/nvidia/nv_proto.h b/drivers/video/nvidia/nv_proto.h
index 6fba656cd56b..861271017655 100644
--- a/drivers/video/nvidia/nv_proto.h
+++ b/drivers/video/nvidia/nv_proto.h
@@ -68,9 +68,11 @@ extern u8 byte_rev[256];
 #ifdef CONFIG_FB_NVIDIA_BACKLIGHT
 extern void nvidia_bl_init(struct nvidia_par *par);
 extern void nvidia_bl_exit(struct nvidia_par *par);
+extern void nvidia_bl_set_power(struct fb_info *info, int power);
 #else
 static inline void nvidia_bl_init(struct nvidia_par *par) {}
 static inline void nvidia_bl_exit(struct nvidia_par *par) {}
+static inline void nvidia_bl_set_power(struct fb_info *info, int power) {}
 #endif
 
 #endif                          /* __NV_PROTO_H__ */
diff --git a/drivers/video/nvidia/nvidia.c b/drivers/video/nvidia/nvidia.c
index ef58c3825501..9f2066f0745a 100644
--- a/drivers/video/nvidia/nvidia.c
+++ b/drivers/video/nvidia/nvidia.c
@@ -932,16 +932,7 @@ static int nvidiafb_blank(int blank, struct fb_info *info)
         NVWriteSeq(par, 0x01, tmp);
         NVWriteCrtc(par, 0x1a, vesa);
 
-#ifdef CONFIG_FB_NVIDIA_BACKLIGHT
-        mutex_lock(&info->bl_mutex);
-        if (info->bl_dev) {
-                down(&info->bl_dev->sem);
-                info->bl_dev->props->power = blank;
-                info->bl_dev->props->update_status(info->bl_dev);
-                up(&info->bl_dev->sem);
-        }
-        mutex_unlock(&info->bl_mutex);
-#endif
+        nvidia_bl_set_power(info, blank);
 
         NVTRACE_LEAVE();
 
diff --git a/drivers/video/riva/fbdev.c b/drivers/video/riva/fbdev.c
index baf494cecc10..33dddbae5420 100644
--- a/drivers/video/riva/fbdev.c
+++ b/drivers/video/riva/fbdev.c
@@ -277,9 +277,11 @@ static const struct riva_regs reg_template = {
  */
 #define MIN_LEVEL 0x158
 #define MAX_LEVEL 0x534
+#define LEVEL_STEP ((MAX_LEVEL - MIN_LEVEL) / FB_BACKLIGHT_MAX)
 
 static struct backlight_properties riva_bl_data;
 
+/* Call with fb_info->bl_mutex held */
 static int riva_bl_get_level_brightness(struct riva_par *par,
                 int level)
 {
@@ -287,9 +289,7 @@ static int riva_bl_get_level_brightness(struct riva_par *par,
         int nlevel;
 
         /* Get and convert the value */
-        mutex_lock(&info->bl_mutex);
-        nlevel = info->bl_curve[level] * FB_BACKLIGHT_MAX / MAX_LEVEL;
-        mutex_unlock(&info->bl_mutex);
+        nlevel = MIN_LEVEL + info->bl_curve[level] * LEVEL_STEP;
 
         if (nlevel < 0)
                 nlevel = 0;
@@ -301,7 +301,8 @@ static int riva_bl_get_level_brightness(struct riva_par *par,
         return nlevel;
 }
 
-static int riva_bl_update_status(struct backlight_device *bd)
+/* Call with fb_info->bl_mutex held */
+static int __riva_bl_update_status(struct backlight_device *bd)
 {
         struct riva_par *par = class_get_devdata(&bd->class_dev);
         U032 tmp_pcrt, tmp_pmc;
@@ -326,6 +327,19 @@ static int riva_bl_update_status(struct backlight_device *bd)
         return 0;
 }
 
+static int riva_bl_update_status(struct backlight_device *bd)
+{
+        struct riva_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 = __riva_bl_update_status(bd);
+        mutex_unlock(&info->bl_mutex);
+
+        return ret;
+}
+
 static int riva_bl_get_brightness(struct backlight_device *bd)
 {
         return bd->props->brightness;
@@ -338,6 +352,16 @@ static struct backlight_properties riva_bl_data = {
         .max_brightness = (FB_BACKLIGHT_LEVELS - 1),
 };
 
+static void riva_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;
+        __riva_bl_update_status(info->bl_dev);
+        down(&info->bl_dev->sem);
+        mutex_unlock(&info->bl_mutex);
+}
+
 static void riva_bl_init(struct riva_par *par)
 {
         struct fb_info *info = pci_get_drvdata(par->pdev);
@@ -418,6 +442,7 @@ static void riva_bl_exit(struct riva_par *par)
 #else
 static inline void riva_bl_init(struct riva_par *par) {}
 static inline void riva_bl_exit(struct riva_par *par) {}
+static inline void riva_bl_set_power(struct fb_info *info, int power) {}
 #endif /* CONFIG_FB_RIVA_BACKLIGHT */
 
 /* ------------------------------------------------------------------------- *
@@ -1336,16 +1361,7 @@ static int rivafb_blank(int blank, struct fb_info *info)
         SEQout(par, 0x01, tmp);
         CRTCout(par, 0x1a, vesa);
 
-#ifdef CONFIG_FB_RIVA_BACKLIGHT
-        mutex_lock(&info->bl_mutex);
-        if (info->bl_dev) {
-                down(&info->bl_dev->sem);
-                info->bl_dev->props->power = blank;
-                info->bl_dev->props->update_status(info->bl_dev);
-                up(&info->bl_dev->sem);
-        }
-        mutex_unlock(&info->bl_mutex);
-#endif
+        riva_bl_set_power(info, blank);
 
         NVTRACE_LEAVE();