pwm-backlight: handle BL_CORE_FBBLANK state

According to include/linux/backlight.h, the fb_blank field is to be
removed and blank status should preferably be set by setting the
BL_CORE_FBBLANK bit of the state field. This patch ensures this
condition is also taken into account when updating the backlight state.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>

drivers/video/backlight/pwm_bl.c

@@ -41,10 +41,9 @@ static int pwm_backlight_update_status(struct backlight_device *bl)
 	int brightness = bl->props.brightness;
 	int max = bl->props.max_brightness;
 
-	if (bl->props.power != FB_BLANK_UNBLANK)
-		brightness = 0;
-
-	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
+	if (bl->props.power != FB_BLANK_UNBLANK ||
+	    bl->props.fb_blank != FB_BLANK_UNBLANK ||
+	    bl->props.state & BL_CORE_FBBLANK)
 		brightness = 0;
 
 	if (pb->notify)