1 files changed, 30 insertions, 8 deletions

diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c
index 5909e8fa4013..6937aedc0a03 100644
--- a/drivers/acpi/processor_perflib.c
+++ b/drivers/acpi/processor_perflib.c
@@ -56,6 +56,8 @@ static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
 {
 	acpi_status status = 0;
 	unsigned long long ppc = 0;
+	s32 qos_value;
+	int index;
 	int ret;
 
 	if (!pr)
@@ -75,17 +77,30 @@ static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
 		return -ENODEV;
 	}
 
+	index = ppc;
+
+	if (pr->performance_platform_limit == index ||
+	    ppc >= pr->performance->state_count)
+		return 0;
+
 	pr_debug("CPU %d: _PPC is %d - frequency %s limited\n", pr->id,
-		       (int)ppc, ppc ? "" : "not");
+		 index, index ? "is" : "is not");
 
-	pr->performance_platform_limit = (int)ppc;
+	pr->performance_platform_limit = index;
 
-	if (ppc >= pr->performance->state_count ||
-	    unlikely(!freq_qos_request_active(&pr->perflib_req)))
+	if (unlikely(!freq_qos_request_active(&pr->perflib_req)))
 		return 0;
 
-	ret = freq_qos_update_request(&pr->perflib_req,
-			pr->performance->states[ppc].core_frequency * 1000);
+	/*
+	 * If _PPC returns 0, it means that all of the available states can be
+	 * used ("no limit").
+	 */
+	if (index == 0)
+		qos_value = FREQ_QOS_MAX_DEFAULT_VALUE;
+	else
+		qos_value = pr->performance->states[index].core_frequency * 1000;
+
+	ret = freq_qos_update_request(&pr->perflib_req, qos_value);
 	if (ret < 0) {
 		pr_warn("Failed to update perflib freq constraint: CPU%d (%d)\n",
 			pr->id, ret);
@@ -168,9 +183,16 @@ void acpi_processor_ppc_init(struct cpufreq_policy *policy)
 		if (!pr)
 			continue;
 
+		/*
+		 * Reset performance_platform_limit in case there is a stale
+		 * value in it, so as to make it match the "no limit" QoS value
+		 * below.
+		 */
+		pr->performance_platform_limit = 0;
+
 		ret = freq_qos_add_request(&policy->constraints,
-					   &pr->perflib_req,
-					   FREQ_QOS_MAX, INT_MAX);
+					   &pr->perflib_req, FREQ_QOS_MAX,
+					   FREQ_QOS_MAX_DEFAULT_VALUE);
 		if (ret < 0)
 			pr_err("Failed to add freq constraint for CPU%d (%d)\n",
 			       cpu, ret);