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authorLinus Torvalds <torvalds@g5.osdl.org>2006-09-26 11:49:46 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-09-26 11:49:46 -0700
commitdd77a4ee0f3981693d4229aa1d57cea9e526ff47 (patch)
treecb486be20b950201103a03636cbb1e1d180f0098 /drivers/base/power/sysfs.c
parente8216dee838c09776680a6f1a2e54d81f3cdfa14 (diff)
parent7e9f4b2d3e21e87c26025810413ef1592834e63b (diff)
Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6
* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6: (47 commits) Driver core: Don't call put methods while holding a spinlock Driver core: Remove unneeded routines from driver core Driver core: Fix potential deadlock in driver core PCI: enable driver multi-threaded probe Driver Core: add ability for drivers to do a threaded probe sysfs: add proper sysfs_init() prototype drivers/base: check errors drivers/base: Platform notify needs to occur before drivers attach to the device v4l-dev2: handle __must_check add CONFIG_ENABLE_MUST_CHECK add __must_check to device management code Driver core: fixed add_bind_files() definition Driver core: fix comments in drivers/base/power/resume.c sysfs_remove_bin_file: no return value, dump_stack on error kobject: must_check fixes Driver core: add ability for devices to create and remove bin files Class: add support for class interfaces for devices Driver core: create devices/virtual/ tree Driver core: add device_rename function Driver core: add ability for classes to handle devices properly ...
Diffstat (limited to 'drivers/base/power/sysfs.c')
-rw-r--r--drivers/base/power/sysfs.c35
1 files changed, 25 insertions, 10 deletions
diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
index 40d7242a07c..2d47517dbe3 100644
--- 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,
};