Commit 5f55836a authored by Clive Lin's avatar Clive Lin Committed by Rafael J. Wysocki
Browse files

PM: QoS: Add check to make sure CPU latency is non-negative 



CPU latency should never be negative, which will be incorrectly high
when converted to unsigned data type.

Commit 8d366942 ("PM: QoS: Add check to make sure CPU freq is
non-negative") makes sure CPU frequency is non-negative to fix incorrect
behavior in freqency QoS.

Add an analogous check to make sure CPU latency is non-negative so as to
prevent this problem from happening in CPU latency QoS.

Signed-off-by: default avatarClive Lin <clive.lin@mediatek.com>
[ rjw: Changelog edits ]
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 706a7415

kernel/power/qos.c

+7 −2
Original line number Diff line number Diff line
@@ -220,6 +220,11 @@ static struct pm_qos_constraints cpu_latency_constraints = { 
	.type = PM_QOS_MIN,

};



static inline bool cpu_latency_qos_value_invalid(s32 value)

{

	return value < 0 && value != PM_QOS_DEFAULT_VALUE;

}



/**

 * cpu_latency_qos_limit - Return current system-wide CPU latency QoS limit.

 */
@@ -263,7 +268,7 @@ static void cpu_latency_qos_apply(struct pm_qos_request *req, 
 */

void cpu_latency_qos_add_request(struct pm_qos_request *req, s32 value)

{

	if (!req)

	if (!req || cpu_latency_qos_value_invalid(value))

		return;



	if (cpu_latency_qos_request_active(req)) {
@@ -289,7 +294,7 @@ EXPORT_SYMBOL_GPL(cpu_latency_qos_add_request); 
 */

void cpu_latency_qos_update_request(struct pm_qos_request *req, s32 new_value)

{

	if (!req)

	if (!req || cpu_latency_qos_value_invalid(new_value))

		return;



	if (!cpu_latency_qos_request_active(req)) {