backlight/fbcon: Add FB_EVENT_CONBLANK

The backlight class wants notification whenever the console is blanked
but doesn't get this when hardware blanking fails and software blanking
is used. Changing FB_EVENT_BLANK to report both would be a behaviour
change which could confuse the console layer so add a new event for
software blanking and have the backlight class listen for both.
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>

drivers/video/backlight/backlight.c

@@ -28,7 +28,7 @@ static int fb_notifier_callback(struct notifier_block *self,
 	struct fb_event *evdata = data;
 
 	/* If we aren't interested in this event, skip it immediately ... */
-	if (event != FB_EVENT_BLANK)
+	if (event != FB_EVENT_BLANK && event != FB_EVENT_CONBLANK)
 		return 0;
 
 	bd = container_of(self, struct backlight_device, fb_notif);

drivers/video/console/fbcon.c

@@ -2233,6 +2233,8 @@ static int fbcon_switch(struct vc_data *vc)
 static void fbcon_generic_blank(struct vc_data *vc, struct fb_info *info,
 				int blank)
 {
+	struct fb_event event;
+
 	if (blank) {
 		unsigned short charmask = vc->vc_hi_font_mask ?
 			0x1ff : 0xff;
@@ -2243,6 +2245,11 @@ static void fbcon_generic_blank(struct vc_data *vc, struct fb_info *info,
 		fbcon_clear(vc, 0, 0, vc->vc_rows, vc->vc_cols);
 		vc->vc_video_erase_char = oldc;
 	}
+
+
+	event.info = info;
+	event.data = ␣
+	fb_notifier_call_chain(FB_EVENT_CONBLANK, &event);
 }
 
 static int fbcon_blank(struct vc_data *vc, int blank, int mode_switch)

include/linux/fb.h

@@ -516,13 +516,15 @@ struct fb_cursor_user {
 #define FB_EVENT_GET_CONSOLE_MAP        0x07
 /*      CONSOLE-SPECIFIC: set console to framebuffer mapping */
 #define FB_EVENT_SET_CONSOLE_MAP        0x08
-/*      A display blank is requested       */
+/*      A hardware display blank change occured */
 #define FB_EVENT_BLANK                  0x09
 /*      Private modelist is to be replaced */
 #define FB_EVENT_NEW_MODELIST           0x0A
 /*	The resolution of the passed in fb_info about to change and
         all vc's should be changed         */
 #define FB_EVENT_MODE_CHANGE_ALL	0x0B
+/*	A software display blank change occured */
+#define FB_EVENT_CONBLANK               0x0C
 
 struct fb_event {
 	struct fb_info *info;