lcd: fix oops if driver only interested in .set_power

b3b4dc88 · Ben Dooks <[email protected]> · 2008-11-19 15:36:25 -08:00

The LCD driver core calls LCD drivers when either the blanking state or
the display mode has changed, but does not make any check to see if the
called driver has a .set_mode method.

This means if a driver only has a .set_power method then the system will
OOPS on changing mode (and with the console semaphore held so you cannot
easily see the problem).

Fix the problem by ensuring that either callback is valid before use.

Signed-off-by: Ben Dooks <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Commit: b3b4dc8840a8fdbe495723d35cd976d781fd42fa
Parents: c267fd77

Changes

1 files changed · +7 −4

File	Status	Add	Del	Content
drivers/video/backlight/lcd.c	modified	+7	−4	View file

drivers/video/backlight/lcd.c

View file

diff --git a/drivers/video/backlight/lcd.c b/drivers/video/backlight/lcd.c
index 8e1731d..680e57b 100644
--- a/drivers/video/backlight/lcd.c
+++ b/drivers/video/backlight/lcd.c
@@ -42,10 +42,13 @@ static int fb_notifier_callback(struct notifier_block *self,
 
 	mutex_lock(&ld->ops_lock);
 	if (!ld->ops->check_fb || ld->ops->check_fb(ld, evdata->info)) {
-		if (event == FB_EVENT_BLANK)
-			ld->ops->set_power(ld, *(int *)evdata->data);
-		else
-			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;