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path: root/drivers/acpi/thermal.c
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Diffstat (limited to 'drivers/acpi/thermal.c')
-rw-r--r--drivers/acpi/thermal.c46
1 files changed, 33 insertions, 13 deletions
diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c
index 12c0ece746f0..859b1de31ddc 100644
--- a/drivers/acpi/thermal.c
+++ b/drivers/acpi/thermal.c
@@ -174,6 +174,8 @@ struct acpi_thermal {
struct thermal_zone_device *thermal_zone;
int kelvin_offset; /* in millidegrees */
struct work_struct thermal_check_work;
+ struct mutex thermal_check_lock;
+ refcount_t thermal_check_count;
};
/* --------------------------------------------------------------------------
@@ -495,14 +497,6 @@ static int acpi_thermal_get_trip_points(struct acpi_thermal *tz)
return 0;
}
-static void acpi_thermal_check(void *data)
-{
- struct acpi_thermal *tz = data;
-
- thermal_zone_device_update(tz->thermal_zone,
- THERMAL_EVENT_UNSPECIFIED);
-}
-
/* sys I/F for generic thermal sysfs support */
static int thermal_get_temp(struct thermal_zone_device *thermal, int *temp)
@@ -900,6 +894,12 @@ static void acpi_thermal_unregister_thermal_zone(struct acpi_thermal *tz)
Driver Interface
-------------------------------------------------------------------------- */
+static void acpi_queue_thermal_check(struct acpi_thermal *tz)
+{
+ if (!work_pending(&tz->thermal_check_work))
+ queue_work(acpi_thermal_pm_queue, &tz->thermal_check_work);
+}
+
static void acpi_thermal_notify(struct acpi_device *device, u32 event)
{
struct acpi_thermal *tz = acpi_driver_data(device);
@@ -910,17 +910,17 @@ static void acpi_thermal_notify(struct acpi_device *device, u32 event)
switch (event) {
case ACPI_THERMAL_NOTIFY_TEMPERATURE:
- acpi_thermal_check(tz);
+ acpi_queue_thermal_check(tz);
break;
case ACPI_THERMAL_NOTIFY_THRESHOLDS:
acpi_thermal_trips_update(tz, ACPI_TRIPS_REFRESH_THRESHOLDS);
- acpi_thermal_check(tz);
+ acpi_queue_thermal_check(tz);
acpi_bus_generate_netlink_event(device->pnp.device_class,
dev_name(&device->dev), event, 0);
break;
case ACPI_THERMAL_NOTIFY_DEVICES:
acpi_thermal_trips_update(tz, ACPI_TRIPS_REFRESH_DEVICES);
- acpi_thermal_check(tz);
+ acpi_queue_thermal_check(tz);
acpi_bus_generate_netlink_event(device->pnp.device_class,
dev_name(&device->dev), event, 0);
break;
@@ -1020,7 +1020,25 @@ static void acpi_thermal_check_fn(struct work_struct *work)
{
struct acpi_thermal *tz = container_of(work, struct acpi_thermal,
thermal_check_work);
- acpi_thermal_check(tz);
+
+ /*
+ * In general, it is not sufficient to check the pending bit, because
+ * subsequent instances of this function may be queued after one of them
+ * has started running (e.g. if _TMP sleeps). Avoid bailing out if just
+ * one of them is running, though, because it may have done the actual
+ * check some time ago, so allow at least one of them to block on the
+ * mutex while another one is running the update.
+ */
+ if (!refcount_dec_not_one(&tz->thermal_check_count))
+ return;
+
+ mutex_lock(&tz->thermal_check_lock);
+
+ thermal_zone_device_update(tz->thermal_zone, THERMAL_EVENT_UNSPECIFIED);
+
+ refcount_inc(&tz->thermal_check_count);
+
+ mutex_unlock(&tz->thermal_check_lock);
}
static int acpi_thermal_add(struct acpi_device *device)
@@ -1052,6 +1070,8 @@ static int acpi_thermal_add(struct acpi_device *device)
if (result)
goto free_memory;
+ refcount_set(&tz->thermal_check_count, 3);
+ mutex_init(&tz->thermal_check_lock);
INIT_WORK(&tz->thermal_check_work, acpi_thermal_check_fn);
pr_info(PREFIX "%s [%s] (%ld C)\n", acpi_device_name(device),
@@ -1117,7 +1137,7 @@ static int acpi_thermal_resume(struct device *dev)
tz->state.active |= tz->trips.active[i].flags.enabled;
}
- queue_work(acpi_thermal_pm_queue, &tz->thermal_check_work);
+ acpi_queue_thermal_check(tz);
return AE_OK;
}