The patch titled lcd: fix oops if driver only interested in .set_power has been added to the -mm tree. Its filename is lcd-fix-oops-if-driver-only-interested-in-set_power.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: lcd: fix oops if driver only interested in .set_power From: Ben Dooks <ben-linux@xxxxxxxxx> 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@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/video/backlight/lcd.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff -puN drivers/video/backlight/lcd.c~lcd-fix-oops-if-driver-only-interested-in-set_power drivers/video/backlight/lcd.c --- a/drivers/video/backlight/lcd.c~lcd-fix-oops-if-driver-only-interested-in-set_power +++ a/drivers/video/backlight/lcd.c @@ -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; _ Patches currently in -mm which might be from ben-linux@xxxxxxxxx are lcd-fix-oops-if-driver-only-interested-in-set_power.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html