From d1578f33f64731fc1ea662f1b472929bed4fa9a8 Mon Sep 17 00:00:00 2001
From: Alexey Starikovskiy <astarikovskiy@suse.de>
Date: Sat, 1 Sep 2007 00:11:59 +0400
Subject: [PATCH] --- yaml --- r: 71627 b: refs/heads/master c:
 6e2157858ac94530fddbf19dc59ab6b392baf1f3 h: refs/heads/master i:   71625:
 ca4c8bc3c386337872c220a7c9f1559d84b52925   71623:
 6af7aac436c06885e14d5b17410e0acb0c43af34 v: v3

---
 [refs]                       |  2 +-
 trunk/drivers/acpi/thermal.c | 15 ++++++++++-----
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/[refs] b/[refs]
index b9a4789c2462..6045253c48d9 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 21bc42ab852549f4a547d18d77e0e4d1b24ffd96
+refs/heads/master: 6e2157858ac94530fddbf19dc59ab6b392baf1f3
diff --git a/trunk/drivers/acpi/thermal.c b/trunk/drivers/acpi/thermal.c
index 15d5fdc66a96..69ec73b0239d 100644
--- a/trunk/drivers/acpi/thermal.c
+++ b/trunk/drivers/acpi/thermal.c
@@ -195,6 +195,7 @@ struct acpi_thermal {
 	struct acpi_thermal_trips trips;
 	struct acpi_handle_list devices;
 	struct timer_list timer;
+	struct mutex lock;
 };
 
 static const struct file_operations acpi_thermal_state_fops = {
@@ -721,11 +722,15 @@ static void acpi_thermal_check(void *data)
 		return;
 	}
 
+	/* Check if someone else is already running */
+	if (!mutex_trylock(&tz->lock))
+		return;
+
 	state = tz->state;
 
 	result = acpi_thermal_get_temperature(tz);
 	if (result)
-		return;
+		goto unlock;
 
 	memset(&tz->state, 0, sizeof(tz->state));
 
@@ -816,8 +821,8 @@ static void acpi_thermal_check(void *data)
 			add_timer(&(tz->timer));
 		}
 	}
-
-	return;
+      unlock:
+	mutex_unlock(&tz->lock);
 }
 
 /* --------------------------------------------------------------------------
@@ -1254,7 +1259,7 @@ static int acpi_thermal_add(struct acpi_device *device)
 	strcpy(acpi_device_name(device), ACPI_THERMAL_DEVICE_NAME);
 	strcpy(acpi_device_class(device), ACPI_THERMAL_CLASS);
 	acpi_driver_data(device) = tz;
-
+	mutex_init(&tz->lock);
 	result = acpi_thermal_get_info(tz);
 	if (result)
 		goto end;
@@ -1324,7 +1329,7 @@ static int acpi_thermal_remove(struct acpi_device *device, int type)
 	}
 
 	acpi_thermal_remove_fs(device);
-
+	mutex_destroy(&tz->lock);
 	kfree(tz);
 	return 0;
 }