1 files changed, 17 insertions, 30 deletions

diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index 81651032791b..d7b499fe0cd9 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -113,7 +113,7 @@ struct acpi_battery_info {
         acpi_string oem_info;
 };
 
-enum acpi_battery_files{
+enum acpi_battery_files {
         ACPI_BATTERY_INFO = 0,
         ACPI_BATTERY_STATE,
         ACPI_BATTERY_ALARM,
@@ -129,13 +129,14 @@ struct acpi_battery_flags {
 };
 
 struct acpi_battery {
-        struct mutex mutex;
         struct acpi_device *device;
         struct acpi_battery_flags flags;
         struct acpi_buffer bif_data;
         struct acpi_buffer bst_data;
+        struct mutex lock;
         unsigned long alarm;
         unsigned long update_time[ACPI_BATTERY_NUMFILES];
+
 };
 
 inline int acpi_battery_present(struct acpi_battery *battery)
@@ -235,10 +236,10 @@ static int acpi_battery_get_info(struct acpi_battery *battery)
                 return 0;
 
         /* Evaluate _BIF */
-
-        status =
-            acpi_evaluate_object(acpi_battery_handle(battery), "_BIF", NULL,
-                                 &buffer);
+        mutex_lock(&battery->lock);
+        status = acpi_evaluate_object(acpi_battery_handle(battery), "_BIF",
+                                      NULL, &buffer);
+        mutex_unlock(&battery->lock);
         if (ACPI_FAILURE(status)) {
                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BIF"));
                 return -ENODEV;
@@ -285,10 +286,10 @@ static int acpi_battery_get_state(struct acpi_battery *battery)
                 return 0;
 
         /* Evaluate _BST */
-
-        status =
-            acpi_evaluate_object(acpi_battery_handle(battery), "_BST", NULL,
-                                 &buffer);
+        mutex_lock(&battery->lock);
+        status = acpi_evaluate_object(acpi_battery_handle(battery), "_BST",
+                                      NULL, &buffer);
+        mutex_unlock(&battery->lock);
         if (ACPI_FAILURE(status)) {
                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BST"));
                 return -ENODEV;
@@ -336,9 +337,10 @@ static int acpi_battery_set_alarm(struct acpi_battery *battery,
 
         arg0.integer.value = alarm;
 
-        status =
-            acpi_evaluate_object(acpi_battery_handle(battery), "_BTP",
+        mutex_lock(&battery->lock);
+        status = acpi_evaluate_object(acpi_battery_handle(battery), "_BTP",
                                  &arg_list, NULL);
+        mutex_unlock(&battery->lock);
         if (ACPI_FAILURE(status))
                 return -ENODEV;
 
@@ -658,8 +660,6 @@ acpi_battery_write_alarm(struct file *file,
         if (!battery || (count > sizeof(alarm_string) - 1))
                 return -EINVAL;
 
-        mutex_lock(&battery->mutex);
-
         result = acpi_battery_update(battery, 1, &update_result);
         if (result) {
                 result = -ENODEV;
@@ -688,9 +688,7 @@ acpi_battery_write_alarm(struct file *file,
         acpi_battery_check_result(battery, result);
 
         if (!result)
-                result = count;
-
-        mutex_unlock(&battery->mutex);
+                return count;
 
         return result;
 }
@@ -714,8 +712,6 @@ static int acpi_battery_read(int fid, struct seq_file *seq)
         int update_result = ACPI_BATTERY_NONE_UPDATE;
         int update = 0;
 
-        mutex_lock(&battery->mutex);
-
         update = (get_seconds() - battery->update_time[fid] >= update_time);
         update = (update | battery->flags.update[fid]);
 
@@ -733,7 +729,6 @@ static int acpi_battery_read(int fid, struct seq_file *seq)
         result = acpi_read_funcs[fid].print(seq, result);
         acpi_battery_check_result(battery, result);
         battery->flags.update[fid] = result;
-        mutex_unlock(&battery->mutex);
         return result;
 }
 
@@ -897,10 +892,7 @@ static int acpi_battery_add(struct acpi_device *device)
         if (!battery)
                 return -ENOMEM;
 
-        mutex_init(&battery->mutex);
-
-        mutex_lock(&battery->mutex);
-
+        mutex_init(&battery->lock);
         battery->device = device;
         strcpy(acpi_device_name(device), ACPI_BATTERY_DEVICE_NAME);
         strcpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
@@ -936,7 +928,6 @@ static int acpi_battery_add(struct acpi_device *device)
                 kfree(battery);
         }
 
-        mutex_unlock(&battery->mutex);
 
         return result;
 }
@@ -951,8 +942,6 @@ static int acpi_battery_remove(struct acpi_device *device, int type)
 
         battery = acpi_driver_data(device);
 
-        mutex_lock(&battery->mutex);
-
         status = acpi_remove_notify_handler(device->handle,
                                             ACPI_ALL_NOTIFY,
                                             acpi_battery_notify);
@@ -963,9 +952,7 @@ static int acpi_battery_remove(struct acpi_device *device, int type)
 
         kfree(battery->bst_data.pointer);
 
-        mutex_unlock(&battery->mutex);
-
-        mutex_destroy(&battery->mutex);
+        mutex_destroy(&battery->lock);
 
         kfree(battery);