backlight: lcd: Rearrange code in fb_notifier_callback()

First acquire the ops_lock and do all tests while holding it. Rearranges
the code in lcd's fb_notifier_callback() to resemble the callback in
the backlight module. This will simplify later changes to these tests.

v2:
- avoid gotos by using guard(mutex) (Daniel)
- fix typos in commit description (Daniel)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20240906075439.98476-2-tzimmermann@suse.de
Signed-off-by: Lee Jones <lee@kernel.org>

1 files changed, 13 insertions, 12 deletions

diff --git a/drivers/video/backlight/lcd.c b/drivers/video/backlight/lcd.c
index ceec90ca758b..2f57d6867d42 100644
--- a/drivers/video/backlight/lcd.c
+++ b/drivers/video/backlight/lcd.c
@@ -27,24 +27,25 @@
 static int fb_notifier_callback(struct notifier_block *self,
 				 unsigned long event, void *data)
 {
-	struct lcd_device *ld;
+	struct lcd_device *ld = container_of(self, struct lcd_device, fb_notif);
 	struct fb_event *evdata = data;
+	struct fb_info *info = evdata->info;
+
+	guard(mutex)(&ld->ops_lock);
 
-	ld = container_of(self, struct lcd_device, fb_notif);
 	if (!ld->ops)
 		return 0;
+	if (ld->ops->check_fb && !ld->ops->check_fb(ld, info))
+		return 0;
 
-	mutex_lock(&ld->ops_lock);
-	if (!ld->ops->check_fb || ld->ops->check_fb(ld, evdata->info)) {
-		if (event == FB_EVENT_BLANK) {
-			if (ld->ops->set_power)
-				ld->ops->set_power(ld, *(int *)evdata->data);
-		} else {
-			if (ld->ops->set_mode)
-				ld->ops->set_mode(ld, evdata->data);
-		}
+	if (event == FB_EVENT_BLANK) {
+		if (ld->ops->set_power)
+			ld->ops->set_power(ld, *(int *)evdata->data);
+	} else {
+		if (ld->ops->set_mode)
+			ld->ops->set_mode(ld, evdata->data);
 	}
-	mutex_unlock(&ld->ops_lock);
+
 	return 0;
 }