[ACPI] Allow return to active cooling mode once passive mode is entered

http://bugzilla.kernel.org/show_bug.cgi?id=3410
https://bugzilla.novell.com/show_bug.cgi?id=131543

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Konstantin Karasyov <konstantin.a.karasyov@intel.com>
Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
Signed-off-by: Yu Luming <luming.yu@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>

1 files changed, 23 insertions, 15 deletions

diff --git a/drivers/acpi/processor_thermal.c b/drivers/acpi/processor_thermal.c
index 37528c3b64b0..f37584015324 100644
--- a/drivers/acpi/processor_thermal.c
+++ b/drivers/acpi/processor_thermal.c
@@ -101,9 +101,7 @@ static unsigned int acpi_thermal_cpufreq_is_init = 0;
 static int cpu_has_cpufreq(unsigned int cpu)
 {
         struct cpufreq_policy policy;
-        if (!acpi_thermal_cpufreq_is_init)
-                return -ENODEV;
-        if (!cpufreq_get_policy(&policy, cpu))
+        if (!acpi_thermal_cpufreq_is_init || cpufreq_get_policy(&policy, cpu))
                 return -ENODEV;
         return 0;
 }
@@ -127,13 +125,13 @@ static int acpi_thermal_cpufreq_decrease(unsigned int cpu)
         if (!cpu_has_cpufreq(cpu))
                 return -ENODEV;
 
-        if (cpufreq_thermal_reduction_pctg[cpu] >= 20) {
+        if (cpufreq_thermal_reduction_pctg[cpu] > 20)
                 cpufreq_thermal_reduction_pctg[cpu] -= 20;
-                cpufreq_update_policy(cpu);
-                return 0;
-        }
-
-        return -ERANGE;
+        else
+                cpufreq_thermal_reduction_pctg[cpu] = 0;
+        cpufreq_update_policy(cpu);
+        /* We reached max freq again and can leave passive mode */
+        return !cpufreq_thermal_reduction_pctg[cpu];
 }
 
 static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb,
@@ -200,7 +198,7 @@ int acpi_processor_set_thermal_limit(acpi_handle handle, int type)
         int result = 0;
         struct acpi_processor *pr = NULL;
         struct acpi_device *device = NULL;
-        int tx = 0;
+        int tx = 0, max_tx_px = 0;
 
         ACPI_FUNCTION_TRACE("acpi_processor_set_thermal_limit");
 
@@ -259,19 +257,27 @@ int acpi_processor_set_thermal_limit(acpi_handle handle, int type)
                 /* if going down: T-states first, P-states later */
 
                 if (pr->flags.throttling) {
-                        if (tx == 0)
+                        if (tx == 0) {
+                                max_tx_px = 1;
                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                                                   "At minimum throttling state\n"));
-                        else {
+                        } else {
                                 tx--;
                                 goto end;
                         }
                 }
 
                 result = acpi_thermal_cpufreq_decrease(pr->id);
-                if (result == -ERANGE)
+                if (result) {
+                        /*
+                         * We only could get -ERANGE, 1 or 0.
+                         * In the first two cases we reached max freq again.
+                         */
                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                                           "At minimum performance state\n"));
+                        max_tx_px = 1;
+                } else
+                        max_tx_px = 0;
 
                 break;
         }
@@ -290,8 +296,10 @@ int acpi_processor_set_thermal_limit(acpi_handle handle, int type)
                                   pr->limit.thermal.px, pr->limit.thermal.tx));
         } else
                 result = 0;
-
-        return_VALUE(result);
+        if (max_tx_px)
+                return_VALUE(1);
+        else
+                return_VALUE(result);
 }
 
 int acpi_processor_get_limit_info(struct acpi_processor *pr)