Revert "backlight/fbcon: Add FB_EVENT_CONBLANK"

This reverts commit 994efacd.

The justification is that if hw blanking fails (i.e. fbops->fb_blank)
fails, then we still want to shut down the backlight. Which is exactly
_not_ what fb_blank() does and so rather inconsistent if we end up
with different behaviour between fbcon and direct fbdev usage. Given
that the entire notifier maze is getting in the way anyway I figured
it's simplest to revert this not well justified commit.

v2: Add static inline to the dummy version.

Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jingoo Han <jingoohan1@gmail.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Yisheng Xie <ysxie@foxmail.com>
Cc: linux-fbdev@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20190528090304.9388-25-daniel.vetter@ffwll.ch

drivers/video/backlight/backlight.c

@@ -47,7 +47,7 @@ static int fb_notifier_callback(struct notifier_block *self,
 	int fb_blank = 0;
 
 	/* If we aren't interested in this event, skip it immediately ... */
-	if (event != FB_EVENT_BLANK && event != FB_EVENT_CONBLANK)
+	if (event != FB_EVENT_BLANK)
 		return 0;
 
 	bd = container_of(self, struct backlight_device, fb_notif);

drivers/video/fbdev/core/fbcon.c

@@ -2350,8 +2350,6 @@ 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;
@@ -2362,13 +2360,6 @@ 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;
 	}
-
-
-	lock_fb_info(info);
-	event.info = info;
-	event.data = ␣
-	fb_notifier_call_chain(FB_EVENT_CONBLANK, &event);
-	unlock_fb_info(info);
 }
 
 static int fbcon_blank(struct vc_data *vc, int blank, int mode_switch)
@@ -3240,7 +3231,7 @@ int fbcon_fb_registered(struct fb_info *info)
 	return ret;
 }
 
-static void fbcon_fb_blanked(struct fb_info *info, int blank)
+void fbcon_fb_blanked(struct fb_info *info, int blank)
 {
 	struct fbcon_ops *ops = info->fbcon_par;
 	struct vc_data *vc;
@@ -3344,9 +3335,6 @@ static int fbcon_event_notify(struct notifier_block *self,
 		con2fb = event->data;
 		con2fb->framebuffer = con2fb_map[con2fb->console - 1];
 		break;
-	case FB_EVENT_BLANK:
-		fbcon_fb_blanked(info, *(int *)event->data);
-		break;
 	case FB_EVENT_REMAP_ALL_CONSOLE:
 		idx = info->node;
 		fbcon_remap_all(idx);

drivers/video/fbdev/core/fbmem.c

@@ -1068,6 +1068,7 @@ fb_blank(struct fb_info *info, int blank)
 	event.data = ␣
 
 	early_ret = fb_notifier_call_chain(FB_EARLY_EVENT_BLANK, &event);
+	fbcon_fb_blanked(info, blank);
 
 	if (info->fbops->fb_blank)
  		ret = info->fbops->fb_blank(blank, info);

include/linux/fb.h

@@ -137,12 +137,10 @@ 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 hardware display blank change occurred */
+/*      A display blank is requested       */
 #define FB_EVENT_BLANK                  0x09
 /*      Private modelist is to be replaced */
 #define FB_EVENT_MODE_CHANGE_ALL	0x0B
-/*	A software display blank change occurred */
-#define FB_EVENT_CONBLANK               0x0C
 /*      CONSOLE-SPECIFIC: remap all consoles to new fb - for vga_switcheroo */
 #define FB_EVENT_REMAP_ALL_CONSOLE      0x0F
 /*      A hardware display blank early change occurred */

include/linux/fbcon.h

@@ -14,6 +14,7 @@ int fbcon_mode_deleted(struct fb_info *info,
 void fbcon_new_modelist(struct fb_info *info);
 void fbcon_get_requirement(struct fb_info *info,
 			   struct fb_blit_caps *caps);
+void fbcon_fb_blanked(struct fb_info *info, int blank);
 #else
 static inline void fb_console_init(void) {}
 static inline void fb_console_exit(void) {}
@@ -27,6 +28,7 @@ static inline int fbcon_mode_deleted(struct fb_info *info,
 static inline void fbcon_new_modelist(struct fb_info *info) {}
 static inline void fbcon_get_requirement(struct fb_info *info,
 					 struct fb_blit_caps *caps) {}
+static inline void fbcon_fb_blanked(struct fb_info *info, int blank) {}
 #endif
 
 #endif /* _LINUX_FBCON_H */