ACPI: Introduce new device wakeup flag 'prepared'

Introduce additional flag 'prepared' in struct acpi_device_wakeup_flags
and use it to prevent devices from being enable/disabled do wake up the
system multiple times in a row (this does not happen currently, but will
be possible after some of the following patches).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

2 files changed, 23 insertions, 2 deletions

diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index 2e959aa1ef0e..4ab21cb1c8c7 100644
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -363,11 +363,18 @@ int acpi_device_sleep_wake(struct acpi_device *dev,
  */
 int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
 {
-        int i;
+        int i, err;
 
         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;
+
         /* Open power resource */
         for (i = 0; i < dev->wakeup.resources.count; i++) {
                 int ret = acpi_power_on(dev->wakeup.resources.handles[i], dev);
@@ -382,7 +389,11 @@ int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
          * Passing 3 as the third argument below means the device may be placed
          * in arbitrary power state afterwards.
          */
-        return acpi_device_sleep_wake(dev, 1, sleep_state, 3);
+        err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
+        if (!err)
+                dev->wakeup.flags.prepared = 1;
+
+        return err;
 }
 
 /*
@@ -398,6 +409,15 @@ int acpi_disable_wakeup_device_power(struct acpi_device *dev)
         if (!dev || !dev->wakeup.flags.valid)
                 return -EINVAL;
 
+        /*
+         * Do not execute the code below twice in a row without calling
+         * acpi_enable_wakeup_device_power() in between for the same device
+         */
+        if (!dev->wakeup.flags.prepared)
+                return 0;
+
+        dev->wakeup.flags.prepared = 0;
+
         ret = acpi_device_sleep_wake(dev, 0, 0, 0);
         if (ret)
                 return ret;
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 0c21ea3bb672..071daf8db600 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -259,6 +259,7 @@ struct acpi_device_perf {
 /* Wakeup Management */
 struct acpi_device_wakeup_flags {
         u8 valid:1;             /* Can successfully enable wakeup? */
+        u8 prepared:1;          /* Has the wake-up capability been enabled? */
         u8 run_wake:1;          /* Run-Wake GPE devices */
 };