LCD: fix oops if driver only interested in .set_power
From: Ben Dooks <ben-linux@fluff.org>
Date: 2008-11-18 18:31:16
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 <ben-linux@fluff.org> Index: linux.git/drivers/video/backlight/lcd.c ===================================================================
--- linux.git.orig/drivers/video/backlight/lcd.c 2008-11-18 15:07:37.000000000 +0000
+++ linux.git/drivers/video/backlight/lcd.c 2008-11-18 15:08:18.000000000 +0000@@ -42,10 +42,13 @@ static int fb_notifier_callback(struct n 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;
--
Ben (ben@fluff.org, http://www.fluff.org/)
'a smiley only costs 4 bytes'
-------------------------------------------------------------------------
This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
Build the coolest Linux based applications with Moblin SDK & win great prizes
Grand prize is a trip for two to an Open Source event anywhere in the world
http://moblin-contest.org/redirect.php?banner_id=100&url=/