backlight: Rework backlight/fb interaction simplifying, lots
fb_info->bl_mutex is badly thought out and the backlight class doesn't
need it if the framebuffer/backlight register/unregister order is
consistent, particularly after the backlight locking fixes.
Fix the drivers to use the order:
backlight_device_register()
register_framebuffer()
unregister_framebuffer()
backlight_device_unregister()
and turn bl_mutex into a lock for the bl_curve data only.
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
diff --git a/drivers/video/aty/aty128fb.c b/drivers/video/aty/aty128fb.c
index 1c77cfb..ef3e786 100644
--- a/drivers/video/aty/aty128fb.c
+++ b/drivers/video/aty/aty128fb.c
@@ -1697,7 +1697,6 @@
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)
{
@@ -1705,6 +1704,7 @@
int atylevel;
/* Get and convert the value */
+ /* No locking of bl_curve since we read a single value */
atylevel = MAX_LEVEL -
(info->bl_curve[level] * FB_BACKLIGHT_MAX / MAX_LEVEL);
@@ -1724,8 +1724,7 @@
/* That one prevents proper CRT output with LCD off */
#undef BACKLIGHT_DAC_OFF
-/* Call with fb_info->bl_mutex held */
-static int __aty128_bl_update_status(struct backlight_device *bd)
+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);
@@ -1778,19 +1777,6 @@
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;
@@ -1804,14 +1790,10 @@
static void aty128_bl_set_power(struct fb_info *info, int power)
{
- mutex_lock(&info->bl_mutex);
-
if (info->bl_dev) {
info->bl_dev->props->power = power;
- __aty128_bl_update_status(info->bl_dev);
+ backlight_update_status(info->bl_dev);
}
-
- mutex_unlock(&info->bl_mutex);
}
static void aty128_bl_init(struct aty128fb_par *par)
@@ -1838,12 +1820,10 @@
goto error;
}
- mutex_lock(&info->bl_mutex);
info->bl_dev = bd;
fb_bl_default_curve(info, 0,
63 * FB_BACKLIGHT_MAX / MAX_LEVEL,
219 * FB_BACKLIGHT_MAX / MAX_LEVEL);
- mutex_unlock(&info->bl_mutex);
bd->props->brightness = aty128_bl_data.max_brightness;
bd->props->power = FB_BLANK_UNBLANK;
@@ -1864,31 +1844,19 @@
return;
}
-static void aty128_bl_exit(struct aty128fb_par *par)
+static void aty128_bl_exit(struct backlight_device *bd)
{
- struct fb_info *info = pci_get_drvdata(par->pdev);
-
+ if (bd) {
#ifdef CONFIG_PMAC_BACKLIGHT
- mutex_lock(&pmac_backlight_mutex);
-#endif
-
- mutex_lock(&info->bl_mutex);
- if (info->bl_dev) {
-#ifdef CONFIG_PMAC_BACKLIGHT
- if (pmac_backlight == info->bl_dev)
+ mutex_lock(&pmac_backlight_mutex);
+ if (pmac_backlight == bd)
pmac_backlight = NULL;
+ mutex_unlock(&pmac_backlight_mutex);
#endif
-
- backlight_device_unregister(info->bl_dev);
- info->bl_dev = NULL;
+ backlight_device_unregister(bd);
printk("aty128: Backlight unloaded\n");
}
- mutex_unlock(&info->bl_mutex);
-
-#ifdef CONFIG_PMAC_BACKLIGHT
- mutex_unlock(&pmac_backlight_mutex);
-#endif
}
#endif /* CONFIG_FB_ATY128_BACKLIGHT */
@@ -2175,11 +2143,12 @@
par = info->par;
+ unregister_framebuffer(info);
+
#ifdef CONFIG_FB_ATY128_BACKLIGHT
- aty128_bl_exit(par);
+ aty128_bl_exit(info->bl_dev);
#endif
- unregister_framebuffer(info);
#ifdef CONFIG_MTRR
if (par->mtrr.vram_valid)
mtrr_del(par->mtrr.vram, info->fix.smem_start,
diff --git a/drivers/video/aty/atyfb_base.c b/drivers/video/aty/atyfb_base.c
index 3b65293..6646228 100644
--- a/drivers/video/aty/atyfb_base.c
+++ b/drivers/video/aty/atyfb_base.c
@@ -2116,13 +2116,13 @@
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 */
+ /* No locking of bl_curve since we read a single value */
atylevel = info->bl_curve[level] * FB_BACKLIGHT_MAX / MAX_LEVEL;
if (atylevel < 0)
@@ -2133,8 +2133,7 @@
return atylevel;
}
-/* Call with fb_info->bl_mutex held */
-static int __aty_bl_update_status(struct backlight_device *bd)
+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);
@@ -2159,19 +2158,6 @@
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;
@@ -2203,12 +2189,10 @@
goto error;
}
- mutex_lock(&info->bl_mutex);
info->bl_dev = bd;
fb_bl_default_curve(info, 0,
0x3F * FB_BACKLIGHT_MAX / MAX_LEVEL,
0xFF * FB_BACKLIGHT_MAX / MAX_LEVEL);
- mutex_unlock(&info->bl_mutex);
bd->props->brightness = aty_bl_data.max_brightness;
bd->props->power = FB_BLANK_UNBLANK;
@@ -2229,30 +2213,19 @@
return;
}
-static void aty_bl_exit(struct atyfb_par *par)
+static void aty_bl_exit(struct backlight_device *bd)
{
- struct fb_info *info = pci_get_drvdata(par->pdev);
-
+ if (bd) {
#ifdef CONFIG_PMAC_BACKLIGHT
- mutex_lock(&pmac_backlight_mutex);
-#endif
-
- mutex_lock(&info->bl_mutex);
- if (info->bl_dev) {
-#ifdef CONFIG_PMAC_BACKLIGHT
- if (pmac_backlight == info->bl_dev)
+ mutex_lock(&pmac_backlight_mutex);
+ if (pmac_backlight == bd)
pmac_backlight = NULL;
+ mutex_unlock(&pmac_backlight_mutex);
#endif
-
- backlight_device_unregister(info->bl_dev);
+ backlight_device_unregister(bd);
printk("aty: Backlight unloaded\n");
}
- mutex_unlock(&info->bl_mutex);
-
-#ifdef CONFIG_PMAC_BACKLIGHT
- mutex_unlock(&pmac_backlight_mutex);
-#endif
}
#endif /* CONFIG_FB_ATY_BACKLIGHT */
@@ -3705,13 +3678,13 @@
aty_set_crtc(par, &saved_crtc);
par->pll_ops->set_pll(info, &saved_pll);
+ unregister_framebuffer(info);
+
#ifdef CONFIG_FB_ATY_BACKLIGHT
if (M64_HAS(MOBIL_BUS))
- aty_bl_exit(par);
+ aty_bl_exit(info->bl_dev);
#endif
- unregister_framebuffer(info);
-
#ifdef CONFIG_MTRR
if (par->mtrr_reg >= 0) {
mtrr_del(par->mtrr_reg, 0, 0);
diff --git a/drivers/video/aty/radeon_backlight.c b/drivers/video/aty/radeon_backlight.c
index 9cfceca..f94e461 100644
--- a/drivers/video/aty/radeon_backlight.c
+++ b/drivers/video/aty/radeon_backlight.c
@@ -29,17 +29,13 @@
static int radeon_bl_get_level_brightness(struct radeon_bl_privdata *pdata,
int level)
{
- struct fb_info *info = pdata->rinfo->info;
int rlevel;
- mutex_lock(&info->bl_mutex);
-
/* Get and convert the value */
+ /* No locking of bl_curve since we read a single value */
rlevel = pdata->rinfo->info->bl_curve[level] *
FB_BACKLIGHT_MAX / MAX_RADEON_LEVEL;
- mutex_unlock(&info->bl_mutex);
-
if (rlevel < 0)
rlevel = 0;
else if (rlevel > MAX_RADEON_LEVEL)
@@ -187,12 +183,10 @@
machine_is_compatible("PowerBook6,5");
#endif
- mutex_lock(&rinfo->info->bl_mutex);
rinfo->info->bl_dev = bd;
fb_bl_default_curve(rinfo->info, 0,
63 * FB_BACKLIGHT_MAX / MAX_RADEON_LEVEL,
217 * FB_BACKLIGHT_MAX / MAX_RADEON_LEVEL);
- mutex_unlock(&rinfo->info->bl_mutex);
bd->props->brightness = radeon_bl_data.max_brightness;
bd->props->power = FB_BLANK_UNBLANK;
@@ -216,29 +210,22 @@
void radeonfb_bl_exit(struct radeonfb_info *rinfo)
{
-#ifdef CONFIG_PMAC_BACKLIGHT
- mutex_lock(&pmac_backlight_mutex);
-#endif
+ struct backlight_device *bd = rinfo->info->bl_dev;
- mutex_lock(&rinfo->info->bl_mutex);
- if (rinfo->info->bl_dev) {
+ if (bd) {
struct radeon_bl_privdata *pdata;
#ifdef CONFIG_PMAC_BACKLIGHT
- if (pmac_backlight == rinfo->info->bl_dev)
+ mutex_lock(&pmac_backlight_mutex);
+ if (pmac_backlight == bd)
pmac_backlight = NULL;
+ mutex_unlock(&pmac_backlight_mutex);
#endif
-
- pdata = class_get_devdata(&rinfo->info->bl_dev->class_dev);
- backlight_device_unregister(rinfo->info->bl_dev);
+ pdata = class_get_devdata(&bd->class_dev);
+ backlight_device_unregister(bd);
kfree(pdata);
rinfo->info->bl_dev = NULL;
printk("radeonfb: Backlight unloaded\n");
}
- mutex_unlock(&rinfo->info->bl_mutex);
-
-#ifdef CONFIG_PMAC_BACKLIGHT
- mutex_unlock(&pmac_backlight_mutex);
-#endif
}
diff --git a/drivers/video/aty/radeon_base.c b/drivers/video/aty/radeon_base.c
index 0ed577e7c..7e228ad 100644
--- a/drivers/video/aty/radeon_base.c
+++ b/drivers/video/aty/radeon_base.c
@@ -2393,7 +2393,6 @@
if (!rinfo)
return;
- radeonfb_bl_exit(rinfo);
radeonfb_pm_exit(rinfo);
if (rinfo->mon1_EDID)
@@ -2420,6 +2419,8 @@
unregister_framebuffer(info);
+ radeonfb_bl_exit(rinfo);
+
iounmap(rinfo->mmio_base);
iounmap(rinfo->fb_base);
diff --git a/drivers/video/fbsysfs.c b/drivers/video/fbsysfs.c
index 818fb09..40c80c8 100644
--- a/drivers/video/fbsysfs.c
+++ b/drivers/video/fbsysfs.c
@@ -59,7 +59,7 @@
info->device = dev;
#ifdef CONFIG_FB_BACKLIGHT
- mutex_init(&info->bl_mutex);
+ mutex_init(&info->bl_curve_mutex);
#endif
return info;
@@ -445,10 +445,10 @@
/* If there has been an error in the input data, we won't
* reach this loop.
*/
- mutex_lock(&fb_info->bl_mutex);
+ mutex_lock(&fb_info->bl_curve_mutex);
for (i = 0; i < FB_BACKLIGHT_LEVELS; ++i)
fb_info->bl_curve[i] = tmp_curve[i];
- mutex_unlock(&fb_info->bl_mutex);
+ mutex_unlock(&fb_info->bl_curve_mutex);
return count;
}
@@ -466,7 +466,7 @@
if (!fb_info || !fb_info->bl_dev)
return -ENODEV;
- mutex_lock(&fb_info->bl_mutex);
+ mutex_lock(&fb_info->bl_curve_mutex);
for (i = 0; i < FB_BACKLIGHT_LEVELS; i += 8)
len += snprintf(&buf[len], PAGE_SIZE,
"%02x %02x %02x %02x %02x %02x %02x %02x\n",
@@ -478,7 +478,7 @@
fb_info->bl_curve[i + 5],
fb_info->bl_curve[i + 6],
fb_info->bl_curve[i + 7]);
- mutex_unlock(&fb_info->bl_mutex);
+ mutex_unlock(&fb_info->bl_curve_mutex);
return len;
}
@@ -552,6 +552,8 @@
{
unsigned int i, flat, count, range = (max - min);
+ mutex_lock(&fb_info->bl_curve_mutex);
+
fb_info->bl_curve[0] = off;
for (flat = 1; flat < (FB_BACKLIGHT_LEVELS / 16); ++flat)
@@ -560,6 +562,8 @@
count = FB_BACKLIGHT_LEVELS * 15 / 16;
for (i = 0; i < count; ++i)
fb_info->bl_curve[flat + i] = min + (range * (i + 1) / count);
+
+ mutex_unlock(&fb_info->bl_curve_mutex);
}
EXPORT_SYMBOL_GPL(fb_bl_default_curve);
#endif
diff --git a/drivers/video/nvidia/nv_backlight.c b/drivers/video/nvidia/nv_backlight.c
index 695b6bf..2bebfee 100644
--- a/drivers/video/nvidia/nv_backlight.c
+++ b/drivers/video/nvidia/nv_backlight.c
@@ -30,7 +30,6 @@
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)
{
@@ -38,6 +37,7 @@
int nlevel;
/* Get and convert the value */
+ /* No locking of bl_curve since we read a single value */
nlevel = MIN_LEVEL + info->bl_curve[level] * LEVEL_STEP;
if (nlevel < 0)
@@ -50,8 +50,7 @@
return nlevel;
}
-/* Call with fb_info->bl_mutex held */
-static int __nvidia_bl_update_status(struct backlight_device *bd)
+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;
@@ -85,19 +84,6 @@
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;
@@ -133,12 +119,10 @@
goto error;
}
- mutex_lock(&info->bl_mutex);
info->bl_dev = bd;
fb_bl_default_curve(info, 0,
0x158 * FB_BACKLIGHT_MAX / MAX_LEVEL,
0x534 * FB_BACKLIGHT_MAX / MAX_LEVEL);
- mutex_unlock(&info->bl_mutex);
bd->props->brightness = nvidia_bl_data.max_brightness;
bd->props->power = FB_BLANK_UNBLANK;
@@ -162,25 +146,17 @@
void nvidia_bl_exit(struct nvidia_par *par)
{
struct fb_info *info = pci_get_drvdata(par->pci_dev);
+ struct backlight_device *bd = info->bl_dev;
+ if (bd) {
#ifdef CONFIG_PMAC_BACKLIGHT
- mutex_lock(&pmac_backlight_mutex);
-#endif
-
- mutex_lock(&info->bl_mutex);
- if (info->bl_dev) {
-#ifdef CONFIG_PMAC_BACKLIGHT
- if (pmac_backlight == info->bl_dev)
+ mutex_lock(&pmac_backlight_mutex);
+ if (pmac_backlight == bd)
pmac_backlight = NULL;
+ mutex_unlock(&pmac_backlight_mutex);
#endif
-
- backlight_device_unregister(info->bl_dev);
+ backlight_device_unregister(bd);
printk("nvidia: Backlight unloaded\n");
}
- mutex_unlock(&info->bl_mutex);
-
-#ifdef CONFIG_PMAC_BACKLIGHT
- mutex_unlock(&pmac_backlight_mutex);
-#endif
}
diff --git a/drivers/video/nvidia/nvidia.c b/drivers/video/nvidia/nvidia.c
index 64f5911..c18e955 100644
--- a/drivers/video/nvidia/nvidia.c
+++ b/drivers/video/nvidia/nvidia.c
@@ -1350,9 +1350,10 @@
NVTRACE_ENTER();
+ unregister_framebuffer(info);
+
nvidia_bl_exit(par);
- unregister_framebuffer(info);
#ifdef CONFIG_MTRR
if (par->mtrr.vram_valid)
mtrr_del(par->mtrr.vram, info->fix.smem_start,
diff --git a/drivers/video/riva/fbdev.c b/drivers/video/riva/fbdev.c
index 9e7d3fc..ab00350 100644
--- a/drivers/video/riva/fbdev.c
+++ b/drivers/video/riva/fbdev.c
@@ -282,7 +282,6 @@
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)
{
@@ -290,6 +289,7 @@
int nlevel;
/* Get and convert the value */
+ /* No locking on bl_curve since accessing a single value */
nlevel = MIN_LEVEL + info->bl_curve[level] * LEVEL_STEP;
if (nlevel < 0)
@@ -302,8 +302,7 @@
return nlevel;
}
-/* Call with fb_info->bl_mutex held */
-static int __riva_bl_update_status(struct backlight_device *bd)
+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;
@@ -328,19 +327,6 @@
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;
@@ -376,12 +362,10 @@
goto error;
}
- mutex_lock(&info->bl_mutex);
info->bl_dev = bd;
fb_bl_default_curve(info, 0,
MIN_LEVEL * FB_BACKLIGHT_MAX / MAX_LEVEL,
FB_BACKLIGHT_MAX);
- mutex_unlock(&info->bl_mutex);
bd->props->brightness = riva_bl_data.max_brightness;
bd->props->power = FB_BLANK_UNBLANK;
@@ -402,34 +386,25 @@
return;
}
-static void riva_bl_exit(struct riva_par *par)
+static void riva_bl_exit(struct fb_info *info)
{
- struct fb_info *info = pci_get_drvdata(par->pdev);
+ struct backlight_device *bd = info->bl_dev;
+ if (bd) {
#ifdef CONFIG_PMAC_BACKLIGHT
- mutex_lock(&pmac_backlight_mutex);
-#endif
-
- mutex_lock(&info->bl_mutex);
- if (info->bl_dev) {
-#ifdef CONFIG_PMAC_BACKLIGHT
- if (pmac_backlight == info->bl_dev)
+ mutex_lock(&pmac_backlight_mutex);
+ if (pmac_backlight == bd)
pmac_backlight = NULL;
+ mutex_unlock(&pmac_backlight_mutex);
#endif
-
- backlight_device_unregister(info->bl_dev);
+ backlight_device_unregister(bd);
printk("riva: Backlight unloaded\n");
}
- mutex_unlock(&info->bl_mutex);
-
-#ifdef CONFIG_PMAC_BACKLIGHT
- mutex_unlock(&pmac_backlight_mutex);
-#endif
}
#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_exit(struct fb_info *info) {}
#endif /* CONFIG_FB_RIVA_BACKLIGHT */
/* ------------------------------------------------------------------------- *
@@ -2146,14 +2121,15 @@
NVTRACE_ENTER();
- riva_bl_exit(par);
-
#ifdef CONFIG_FB_RIVA_I2C
riva_delete_i2c_busses(par);
kfree(par->EDID);
#endif
unregister_framebuffer(info);
+
+ riva_bl_exit(info);
+
#ifdef CONFIG_MTRR
if (par->mtrr.vram_valid)
mtrr_del(par->mtrr.vram, info->fix.smem_start,
diff --git a/include/linux/fb.h b/include/linux/fb.h
index bf7158b..be913ec 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -769,16 +769,13 @@
struct fb_videomode *mode; /* current mode */
#ifdef CONFIG_FB_BACKLIGHT
- /* Lock ordering:
- * bl_mutex (protects bl_dev and bl_curve)
- * bl_dev->sem (backlight class)
- */
- struct mutex bl_mutex;
-
/* assigned backlight device */
+ /* set before framebuffer registration,
+ remove after unregister */
struct backlight_device *bl_dev;
/* Backlight level curve */
+ struct mutex bl_curve_mutex;
u8 bl_curve[FB_BACKLIGHT_LEVELS];
#endif
