Merge branch 'writeback' of git://git.kernel.dk/linux-2.6-block

[pandora-kernel.git] / drivers / acpi / power.c

diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index d74365d..22b2979 100644 (file)
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -43,6 +43,9 @@
 #include <linux/seq_file.h>
 #include <acpi/acpi_bus.h>
 #include <acpi/acpi_drivers.h>
+#include "sleep.h"
+
+#define PREFIX "ACPI: "
 
 #define _COMPONENT                     ACPI_POWER_COMPONENT
 ACPI_MODULE_NAME("power");
@@ -361,17 +364,15 @@ int acpi_device_sleep_wake(struct acpi_device *dev,
  */
 int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
 {
-       int i, err;
+       int i, err = 0;
 
        if (!dev || !dev->wakeup.flags.valid)
                return -EINVAL;
 
-       /*
-        * Do not execute the code below twice in a row without calling
-        * acpi_disable_wakeup_device_power() in between for the same device
-        */
-       if (dev->wakeup.flags.prepared)
-               return 0;
+       mutex_lock(&acpi_device_lock);
+
+       if (dev->wakeup.prepare_count++)
+               goto out;
 
        /* Open power resource */
        for (i = 0; i < dev->wakeup.resources.count; i++) {
@@ -379,7 +380,8 @@ int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
                if (ret) {
                        printk(KERN_ERR PREFIX "Transition power state\n");
                        dev->wakeup.flags.valid = 0;
-                       return -ENODEV;
+                       err = -ENODEV;
+                       goto err_out;
                }
        }
 
@@ -388,9 +390,13 @@ int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
         * in arbitrary power state afterwards.
         */
        err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
-       if (!err)
-               dev->wakeup.flags.prepared = 1;
 
+ err_out:
+       if (err)
+               dev->wakeup.prepare_count = 0;
+
+ out:
+       mutex_unlock(&acpi_device_lock);
        return err;
 }
 
@@ -402,35 +408,42 @@ int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
  */
 int acpi_disable_wakeup_device_power(struct acpi_device *dev)
 {
-       int i, ret;
+       int i, err = 0;
 
        if (!dev || !dev->wakeup.flags.valid)
                return -EINVAL;
 
+       mutex_lock(&acpi_device_lock);
+
+       if (--dev->wakeup.prepare_count > 0)
+               goto out;
+
        /*
-        * Do not execute the code below twice in a row without calling
-        * acpi_enable_wakeup_device_power() in between for the same device
+        * Executing the code below even if prepare_count is already zero when
+        * the function is called may be useful, for example for initialisation.
         */
-       if (!dev->wakeup.flags.prepared)
-               return 0;
+       if (dev->wakeup.prepare_count < 0)
+               dev->wakeup.prepare_count = 0;
 
-       dev->wakeup.flags.prepared = 0;
-
-       ret = acpi_device_sleep_wake(dev, 0, 0, 0);
-       if (ret)
-               return ret;
+       err = acpi_device_sleep_wake(dev, 0, 0, 0);
+       if (err)
+               goto out;
 
        /* Close power resource */
        for (i = 0; i < dev->wakeup.resources.count; i++) {
-               ret = acpi_power_off_device(dev->wakeup.resources.handles[i], dev);
+               int ret = acpi_power_off_device(
+                               dev->wakeup.resources.handles[i], dev);
                if (ret) {
                        printk(KERN_ERR PREFIX "Transition power state\n");
                        dev->wakeup.flags.valid = 0;
-                       return -ENODEV;
+                       err = -ENODEV;
+                       goto out;
                }
        }
 
-       return ret;
+ out:
+       mutex_unlock(&acpi_device_lock);
+       return err;
 }
 
 /* --------------------------------------------------------------------------