1 files changed, 39 insertions, 31 deletions

diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c
index e8c143caf0fd..564ea1424288 100644
--- a/drivers/acpi/thermal.c
+++ b/drivers/acpi/thermal.c
@@ -98,6 +98,7 @@ MODULE_PARM_DESC(psv, "Disable or override all passive trip points.");
 static int acpi_thermal_add(struct acpi_device *device);
 static int acpi_thermal_remove(struct acpi_device *device, int type);
 static int acpi_thermal_resume(struct acpi_device *device);
+static void acpi_thermal_notify(struct acpi_device *device, u32 event);
 static int acpi_thermal_state_open_fs(struct inode *inode, struct file *file);
 static int acpi_thermal_temp_open_fs(struct inode *inode, struct file *file);
 static int acpi_thermal_trip_open_fs(struct inode *inode, struct file *file);
@@ -123,6 +124,7 @@ static struct acpi_driver acpi_thermal_driver = {
 		.add = acpi_thermal_add,
 		.remove = acpi_thermal_remove,
 		.resume = acpi_thermal_resume,
+		.notify = acpi_thermal_notify,
 		},
 };
 
@@ -192,6 +194,7 @@ struct acpi_thermal {
 	struct acpi_handle_list devices;
 	struct thermal_zone_device *thermal_zone;
 	int tz_enabled;
+	int kelvin_offset;
 	struct mutex lock;
 };
 
@@ -581,7 +584,7 @@ static void acpi_thermal_check(void *data)
 }
 
 /* sys I/F for generic thermal sysfs support */
-#define KELVIN_TO_MILLICELSIUS(t) (t * 100 - 273200)
+#define KELVIN_TO_MILLICELSIUS(t, off) (((t) - (off)) * 100)
 
 static int thermal_get_temp(struct thermal_zone_device *thermal,
 			    unsigned long *temp)
@@ -596,7 +599,7 @@ static int thermal_get_temp(struct thermal_zone_device *thermal,
 	if (result)
 		return result;
 
-	*temp = KELVIN_TO_MILLICELSIUS(tz->temperature);
+	*temp = KELVIN_TO_MILLICELSIUS(tz->temperature, tz->kelvin_offset);
 	return 0;
 }
 
@@ -702,7 +705,8 @@ static int thermal_get_trip_temp(struct thermal_zone_device *thermal,
 	if (tz->trips.critical.flags.valid) {
 		if (!trip) {
 			*temp = KELVIN_TO_MILLICELSIUS(
-				tz->trips.critical.temperature);
+				tz->trips.critical.temperature,
+				tz->kelvin_offset);
 			return 0;
 		}
 		trip--;
@@ -711,7 +715,8 @@ static int thermal_get_trip_temp(struct thermal_zone_device *thermal,
 	if (tz->trips.hot.flags.valid) {
 		if (!trip) {
 			*temp = KELVIN_TO_MILLICELSIUS(
-				tz->trips.hot.temperature);
+				tz->trips.hot.temperature,
+				tz->kelvin_offset);
 			return 0;
 		}
 		trip--;
@@ -720,7 +725,8 @@ static int thermal_get_trip_temp(struct thermal_zone_device *thermal,
 	if (tz->trips.passive.flags.valid) {
 		if (!trip) {
 			*temp = KELVIN_TO_MILLICELSIUS(
-				tz->trips.passive.temperature);
+				tz->trips.passive.temperature,
+				tz->kelvin_offset);
 			return 0;
 		}
 		trip--;
@@ -730,7 +736,8 @@ static int thermal_get_trip_temp(struct thermal_zone_device *thermal,
 		tz->trips.active[i].flags.valid; i++) {
 		if (!trip) {
 			*temp = KELVIN_TO_MILLICELSIUS(
-				tz->trips.active[i].temperature);
+				tz->trips.active[i].temperature,
+				tz->kelvin_offset);
 			return 0;
 		}
 		trip--;
@@ -745,7 +752,8 @@ static int thermal_get_crit_temp(struct thermal_zone_device *thermal,
 
 	if (tz->trips.critical.flags.valid) {
 		*temperature = KELVIN_TO_MILLICELSIUS(
-				tz->trips.critical.temperature);
+				tz->trips.critical.temperature,
+				tz->kelvin_offset);
 		return 0;
 	} else
 		return -EINVAL;
@@ -901,7 +909,7 @@ static int acpi_thermal_register_thermal_zone(struct acpi_thermal *tz)
 			thermal_zone_device_register("acpitz", trips, tz,
 						     &acpi_thermal_zone_ops,
 						     0, 0, 0,
-						     tz->polling_frequency);
+						     tz->polling_frequency*100);
 	if (IS_ERR(tz->thermal_zone))
 		return -ENODEV;
 
@@ -1264,17 +1272,14 @@ static int acpi_thermal_remove_fs(struct acpi_device *device)
                                  Driver Interface
    -------------------------------------------------------------------------- */
 
-static void acpi_thermal_notify(acpi_handle handle, u32 event, void *data)
+static void acpi_thermal_notify(struct acpi_device *device, u32 event)
 {
-	struct acpi_thermal *tz = data;
-	struct acpi_device *device = NULL;
+	struct acpi_thermal *tz = acpi_driver_data(device);
 
 
 	if (!tz)
 		return;
 
-	device = tz->device;
-
 	switch (event) {
 	case ACPI_THERMAL_NOTIFY_TEMPERATURE:
 		acpi_thermal_check(tz);
@@ -1298,8 +1303,6 @@ static void acpi_thermal_notify(acpi_handle handle, u32 event, void *data)
 				  "Unsupported event [0x%x]\n", event));
 		break;
 	}
-
-	return;
 }
 
 static int acpi_thermal_get_info(struct acpi_thermal *tz)
@@ -1334,10 +1337,28 @@ static int acpi_thermal_get_info(struct acpi_thermal *tz)
 	return 0;
 }
 
+/*
+ * The exact offset between Kelvin and degree Celsius is 273.15. However ACPI
+ * handles temperature values with a single decimal place. As a consequence,
+ * some implementations use an offset of 273.1 and others use an offset of
+ * 273.2. Try to find out which one is being used, to present the most
+ * accurate and visually appealing number.
+ *
+ * The heuristic below should work for all ACPI thermal zones which have a
+ * critical trip point with a value being a multiple of 0.5 degree Celsius.
+ */
+static void acpi_thermal_guess_offset(struct acpi_thermal *tz)
+{
+	if (tz->trips.critical.flags.valid &&
+	    (tz->trips.critical.temperature % 5) == 1)
+		tz->kelvin_offset = 2731;
+	else
+		tz->kelvin_offset = 2732;
+}
+
 static int acpi_thermal_add(struct acpi_device *device)
 {
 	int result = 0;
-	acpi_status status = AE_OK;
 	struct acpi_thermal *tz = NULL;
 
 
@@ -1360,6 +1381,8 @@ static int acpi_thermal_add(struct acpi_device *device)
 	if (result)
 		goto free_memory;
 
+	acpi_thermal_guess_offset(tz);
+
 	result = acpi_thermal_register_thermal_zone(tz);
 	if (result)
 		goto free_memory;
@@ -1368,21 +1391,11 @@ static int acpi_thermal_add(struct acpi_device *device)
 	if (result)
 		goto unregister_thermal_zone;
 
-	status = acpi_install_notify_handler(device->handle,
-					     ACPI_DEVICE_NOTIFY,
-					     acpi_thermal_notify, tz);
-	if (ACPI_FAILURE(status)) {
-		result = -ENODEV;
-		goto remove_fs;
-	}
-
 	printk(KERN_INFO PREFIX "%s [%s] (%ld C)\n",
 	       acpi_device_name(device), acpi_device_bid(device),
 	       KELVIN_TO_CELSIUS(tz->temperature));
 	goto end;
 
-remove_fs:
-	acpi_thermal_remove_fs(device);
 unregister_thermal_zone:
 	thermal_zone_device_unregister(tz->thermal_zone);
 free_memory:
@@ -1393,7 +1406,6 @@ end:
 
 static int acpi_thermal_remove(struct acpi_device *device, int type)
 {
-	acpi_status status = AE_OK;
 	struct acpi_thermal *tz = NULL;
 
 	if (!device || !acpi_driver_data(device))
@@ -1401,10 +1413,6 @@ static int acpi_thermal_remove(struct acpi_device *device, int type)
 
 	tz = acpi_driver_data(device);
 
-	status = acpi_remove_notify_handler(device->handle,
-					    ACPI_DEVICE_NOTIFY,
-					    acpi_thermal_notify);
-
 	acpi_thermal_remove_fs(device);
 	acpi_thermal_unregister_thermal_zone(tz);
 	mutex_destroy(&tz->lock);