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,