[PATCH] console blanking oops fix

When significant delays happen during boot (e.g.  with a kernel debugger,
but the problem has also seen in other cases) the timeout for blanking the
console may trigger, but the work scheduler may not have been initialized,
yet.  schedule_work() will oops over the null keventd_wq.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/char/vt.c b/drivers/char/vt.c
index e5ef1dfc5482..d7aa7a29f67e 100644
--- a/drivers/char/vt.c
+++ b/drivers/char/vt.c
@@ -2867,6 +2867,10 @@ void unblank_screen(void)
  */
 static void blank_screen_t(unsigned long dummy)
 {
+        if (unlikely(!keventd_up())) {
+                mod_timer(&console_timer, jiffies + blankinterval);
+                return;
+        }
         blank_timer_expired = 1;
         schedule_work(&console_work);
 }