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/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