From ee01e663373343c63e0e3d364d09f6155378dbcc Mon Sep 17 00:00:00 2001 From: Toshi Kani Date: Sat, 31 Mar 2012 21:37:02 -0600 Subject: [PATCH] cpuidle: Fix panic in CPU off-lining with no idle driver Fix a NULL pointer dereference panic in cpuidle_play_dead() during CPU off-lining when no cpuidle driver is registered. A cpuidle driver may be registered at boot-time based on CPU type. This patch allows an off-lined CPU to enter HLT-based idle in this condition. Signed-off-by: Toshi Kani Cc: Boris Ostrovsky Reviewed-by: Srivatsa S. Bhat Tested-by: Srivatsa S. Bhat Signed-off-by: Len Brown --- drivers/cpuidle/cpuidle.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 3e146b2ada4a..a71376a45d8e 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -74,7 +74,7 @@ static cpuidle_enter_t cpuidle_enter_ops; /** * cpuidle_play_dead - cpu off-lining * - * Only returns in case of an error + * Returns in case of an error or no driver */ int cpuidle_play_dead(void) { @@ -83,6 +83,9 @@ int cpuidle_play_dead(void) int i, dead_state = -1; int power_usage = -1; + if (!drv) + return -ENODEV; + /* Find lowest-power state that supports long-term idle */ for (i = CPUIDLE_DRIVER_STATE_START; i < drv->state_count; i++) { struct cpuidle_state *s = &drv->states[i];