From: Alexey Starikovskiy <astarikovskiy@xxxxxxx>
Fix for #3686, where get_temperature() may cause thermal notify, which
causes one more get_temperature().
Signed-off-by: Alexey Starikovskiy <astarikovskiy@xxxxxxx>
Signed-off-by: Len Brown <len.brown@xxxxxxxxx>
---
drivers/acpi/thermal.c | 15 ++++++++++-----
1 files changed, 10 insertions(+), 5 deletions(-)
diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c
index 15d5fdc..69ec73b 100644
--- a/drivers/acpi/thermal.c
+++ b/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;
}
--
1.5.3.4.206.g58ba4
-
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