Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit ee01e663 authored by Toshi Kani's avatar Toshi Kani Committed by Len Brown
Browse files

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: default avatarToshi Kani <toshi.kani@hp.com>
Cc: Boris Ostrovsky <boris.ostrovsky@amd.com>
Reviewed-by: default avatarSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Tested-by: default avatarSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 54f70077

drivers/cpuidle/cpuidle.c

+4 −1
Original line number Original line Diff line number Diff line
@@ -74,7 +74,7 @@ static cpuidle_enter_t cpuidle_enter_ops; 
/**

/**

 * cpuidle_play_dead - cpu off-lining

 * 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)

int cpuidle_play_dead(void)

{

{
@@ -83,6 +83,9 @@ int cpuidle_play_dead(void) 
	int i, dead_state = -1;

	int i, dead_state = -1;

	int power_usage = -1;

	int power_usage = -1;





	if (!drv)

		return -ENODEV;



	/* Find lowest-power state that supports long-term idle */

	/* Find lowest-power state that supports long-term idle */

	for (i = CPUIDLE_DRIVER_STATE_START; i < drv->state_count; i++) {

	for (i = CPUIDLE_DRIVER_STATE_START; i < drv->state_count; i++) {

		struct cpuidle_state *s = &drv->states[i];

		struct cpuidle_state *s = &drv->states[i];