fedora core 6 1.2949 + vserver 2.2.0

[linux-2.6.git] / drivers / base / power / sysfs.c

diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
index 40d7242..2d47517 100644 (file)
--- a/drivers/base/power/sysfs.c
+++ b/drivers/base/power/sysfs.c
@@ -7,22 +7,29 @@
 #include "power.h"
 
 
+#ifdef CONFIG_PM_SYSFS_DEPRECATED
+
 /**
  *     state - Control current power state of device
  *
  *     show() returns the current power state of the device. '0' indicates
- *     the device is on. Other values (1-3) indicate the device is in a low
+ *     the device is on. Other values (2) indicate the device is in some low
  *     power state.
  *
- *     store() sets the current power state, which is an integer value
- *     between 0-3. If the device is on ('0'), and the value written is
- *     greater than 0, then the device is placed directly into the low-power
- *     state (via its driver's ->suspend() method).
- *     If the device is currently in a low-power state, and the value is 0,
- *     the device is powered back on (via the ->resume() method).
- *     If the device is in a low-power state, and a different low-power state
- *     is requested, the device is first resumed, then suspended into the new
- *     low-power state.
+ *     store() sets the current power state, which is an integer valued
+ *     0, 2, or 3.  Devices with bus.suspend_late(), or bus.resume_early()
+ *     methods fail this operation; those methods couldn't be called.
+ *     Otherwise,
+ *
+ *     - If the recorded dev->power.power_state.event matches the
+ *       target value, nothing is done.
+ *     - If the recorded event code is nonzero, the device is reactivated
+ *       by calling bus.resume() and/or class.resume().
+ *     - If the target value is nonzero, the device is suspended by
+ *       calling class.suspend() and/or bus.suspend() with event code
+ *       PM_EVENT_SUSPEND.
+ *
+ *     This mechanism is DEPRECATED and should only be used for testing.
  */
 
 static ssize_t state_show(struct device * dev, struct device_attribute *attr, char * buf)
@@ -38,6 +45,10 @@ static ssize_t state_store(struct device * dev, struct device_attribute *attr, c
        pm_message_t state;
        int error = -EINVAL;
 
+       /* disallow incomplete suspend sequences */
+       if (dev->bus && (dev->bus->suspend_late || dev->bus->resume_early))
+               return error;
+
        state.event = PM_EVENT_SUSPEND;
        /* Older apps expected to write "3" here - confused with PCI D3 */
        if ((n == 1) && !strcmp(buf, "3"))
@@ -57,6 +68,8 @@ static ssize_t state_store(struct device * dev, struct device_attribute *attr, c
 static DEVICE_ATTR(state, 0644, state_show, state_store);
 
 
+#endif /* CONFIG_PM_SYSFS_DEPRECATED */
+
 /*
  *     wakeup - Report/change current wakeup option for device
  *
@@ -130,7 +143,9 @@ static DEVICE_ATTR(wakeup, 0644, wake_show, wake_store);
 
 
 static struct attribute * power_attrs[] = {
+#ifdef CONFIG_PM_SYSFS_DEPRECATED
        &dev_attr_state.attr,
+#endif
        &dev_attr_wakeup.attr,
        NULL,
 };