On Sunday, 9 of March 2008, Alan Stern wrote:
> On Sun, 9 Mar 2008, Rafael J. Wysocki wrote:
>
> > > Didn't we decide it would be better to call @prepare in a separate
> > > pass?
> >
> > Afterwards I realized that it would be racy. Namely, once a new device is
> > registered, it may require ->prepare() to be called before ->suspend(), so if
> > that happens after we've called ->prepare() for all devices, we'll be in
> > trouble.
>
> There's nothing wrong with doing it this way. However the race you're
> worried about will never happen if drivers are written correctly. Once
> prepare has been called for all devices, no new devices should be
> registered.
That only applies to the devices with parents. Apart from this, the device
can be registered concurrently with its parent's ->prepare() and in that case
we should call ->complete() for the parent etc. IOW, almost the same
complications as in dpm_suspend() would have to be taken into account.
[--snip--]
> > + * @prepare: Prepare the device for the upcoming transition, but do NOT change
> > + * its hardware state. Prevent new children of the device from being
> > + * registered and prevent new calls to the probe method from being made
> > + * after @prepare() returns. Also, if a concurrent child registration
> > + * or a call to the probe method already in progress is detected by
> > + * @prepare(), it may return -EAGAIN, so that the PM core can execute it
> > + * once again (e.g. after suspending the newly registered child) to recover
> > + * from the race condition. This method is executed for all kinds of
> > + * suspend transitions and is immediately followed by one of the suspend
> > + * callbacks: @suspend(), @freeze(), @poweroff(), or @quiesce().
> > + * [NOTE: The PM core is able to detect a registration of a new child of a
> > + * device concurrent with this device's @prepare() callback, in which case
> > + * @complete() will be called for the device and the core will try again to
> > + * suspend it later. However, the core is NOT able to handle a call to
> > + * the probe method concurrent with @prepare().]
>
> I think you can leave out this NOTE. Direct probe method calls by
> drivers are pretty rare; almost all probing is done by the driver core.
Done.
> > + * @complete: Undo the changes made by @prepare(). This method is executed for
> > + * all kinds of resume transitions, immediately following one of the resume
> > + * callbacks: @resume(), @thaw(), @restore(), or @recover(). Also executed
> > + * if a suspend callback (@suspend(), @freeze(), @poweroff(), @quiesce())
> > + * immediately following a successful @prepare() fails OR if @prepare()
> > + * returns -EAGAIN.
>
> The last part is wrong.
Yes, I noticed that too.
> If @prepare returns an error (such as -EAGAIN) then @complete shouldn't be called.
Hmm, I'd prefer to call it if ->prepare() fails too. The -EAGAIN case is
special, because in fact there's no warranty that ->prepare() will be called
again (for example, the new child's ->suspend() may fail before that happens),
so we need to do the clean up after it. In general, if ->complete() is assumed
to be called after a failing ->prepare() too, that simplifies the code a bit.
[--snip--]
>
> > +enum dpm_state {
> > + DPM_ON,
> > + DPM_SUSPENDING,
> > + DPM_OFF,
> > +};
>
> There should be kerneldoc for dpm_state.
In fact there is one, right above the definition of 'enum dpm_state'. It was
placed a bit confusingly under the big comment about the legacy stuff.
I changed the ordering of things in pm.h to avoid that confusion.
[--snip--]
>
> > @@ -71,22 +71,29 @@ int device_pm_add(struct device *dev)
> > dev->bus ? dev->bus->name : "No Bus",
> > kobject_name(&dev->kobj));
> > mutex_lock(&dpm_list_mtx);
> > - if ((dev->parent && dev->parent->power.sleeping) || all_sleeping) {
> > - if (dev->parent->power.sleeping)
> > - dev_warn(dev,
> > - "parent %s is sleeping, will not add\n",
> > + if (all_sleeping) {
> > + dev_warn(dev, "devices are sleeping, will not add\n");
> > + goto Failure;
> > + }
> > + if (dev->parent) {
> > + if (dev->parent->power.status == DPM_OFF) {
> > + dev_warn(dev, "parent %s is sleeping, will not add\n",
> > dev->parent->bus_id);
> > - else
> > - dev_warn(dev, "devices are sleeping, will not add\n");
> > - WARN_ON(true);
> > - error = -EBUSY;
> > - } else {
> > - error = dpm_sysfs_add(dev);
> > - if (!error)
> > - list_add_tail(&dev->power.entry, &dpm_active);
> > + goto Failure;
> > + } else if (dev->parent->power.status == DPM_SUSPENDING) {
> > + dev->parent->power.status == DPM_ON;
> > + }
>
> This part puzzled me until I read the rest of the patch. It's a good
> way to look specifically for new _child_ registrations as opposed to
> any new registrations.
I reworked that a bit.
> > @@ -418,22 +629,37 @@ static int dpm_suspend(pm_message_t stat
> > struct list_head *entry = dpm_active.prev;
> > struct device *dev = to_device(entry);
> >
> > - WARN_ON(dev->parent && dev->parent->power.sleeping);
> > + WARN_ON(dev->parent && dev->parent->power.status == DPM_OFF);
> > + dev->power.status = DPM_SUSPENDING;
> > + mutex_unlock(&dpm_list_mtx);
> > +
> > + error = prepare_device(dev, state);
> > +
> > + mutex_lock(&dpm_list_mtx);
> > + if (error == -EAGAIN)
> > + dev->power.status = DPM_ON;
> > + else if(error)
> > + break;
>
> The last four lines should be:
>
> if (error) {
> dev->power.status = DPM_ON;
> if (error == -EAGAIN)
> continue;
> break;
> }
Well, I reworked this part too, but in a different way.
> Insert: /* Was a child added during prepare_device()? */
I added a different comment here.
> > + if (dev->power.status == DPM_ON) {
> > + mutex_unlock(&dpm_list_mtx);
> > +
> > + complete_device(dev, resume_event(state));
> >
> > - dev->power.sleeping = true;
> > + mutex_lock(&dpm_list_mtx);
> > + continue;
> > + }
> > + dev->power.status = DPM_OFF;
> > mutex_unlock(&dpm_list_mtx);
> > +
> > error = suspend_device(dev, state);
> > +
> > mutex_lock(&dpm_list_mtx);
> > if (error) {
> > - printk(KERN_ERR "Could not suspend device %s: "
> > - "error %d%s\n",
> > - kobject_name(&dev->kobj),
> > - error,
> > - (error == -EAGAIN ?
> > - " (please convert to suspend_late)" :
> > - ""));
> > - dev->power.sleeping = false;
> > - break;
> > + dev->power.status = DPM_ON;
> > + mutex_unlock(&dpm_list_mtx);
> > +
> > + complete_device(dev, resume_event(state));
> > + return error;
>
> Early return? I guess it's okay...
>
> > }
> > if (!list_empty(&dev->power.entry))
> > list_move(&dev->power.entry, &dpm_off);
>
> Looks good.
Well, I reworked it somewhat in the meantime.
First, I moved the pm_dev_dbg() stuff into the inner if () blocks.
Second, I made it possible to use ->prepare() and ->complete() in the
"noirq" case as well and added a comment about the "noirq" callbacks.
Finally, I cut some rough edges here and there (at least I hope so).
The new patch is appended.
Thanks,
Rafael
---
arch/x86/kernel/apm_32.c | 4
drivers/base/power/main.c | 463 +++++++++++++++++++++++++++++++++++-----------
include/linux/device.h | 8
include/linux/pm.h | 238 ++++++++++++++++++++---
kernel/power/disk.c | 14 -
kernel/power/main.c | 4
6 files changed, 579 insertions(+), 152 deletions(-)
Index: linux-2.6/include/linux/pm.h
===================================================================
--- linux-2.6.orig/include/linux/pm.h
+++ linux-2.6/include/linux/pm.h
@@ -110,11 +110,9 @@ extern void (*pm_power_off_prepare)(void
struct device;
-typedef struct pm_message {
- int event;
-} pm_message_t;
-
-/*
+/**
+ * struct pm_ops - device PM callbacks
+ *
* Several driver power state transitions are externally visible, affecting
* the state of pending I/O queues and (for drivers that touch hardware)
* interrupts, wakeups, DMA, and other hardware state. There may also be
@@ -122,6 +120,206 @@ typedef struct pm_message {
* to the rest of the driver stack (such as a driver that's ON gating off
* clocks which are not in active use).
*
+ * The externally visible transitions are handled with the help of the following
+ * callbacks included in this structure:
+ *
+ * @prepare: Prepare the device for the upcoming transition, but do NOT change
+ * its hardware state. Prevent new children of the device from being
+ * registered and prevent new calls to the probe method from being made
+ * after @prepare() returns. Also, if a concurrent child registration
+ * or a call to the probe method already in progress is detected by
+ * @prepare(), it may return -EAGAIN, so that the PM core can execute it
+ * once again (e.g. after suspending the newly registered child) to recover
+ * from the race condition. This method is executed for all kinds of
+ * suspend transitions and is immediately followed by one of the suspend
+ * callbacks: @suspend(), @freeze(), @poweroff(), or @quiesce().
+ *
+ * @complete: Undo the changes made by @prepare(). This method is executed for
+ * all kinds of resume transitions, immediately following one of the resume
+ * callbacks: @resume(), @thaw(), @restore(), or @recover(). Also executed
+ * if a suspend callback (@suspend(), @freeze(), @poweroff(), @quiesce())
+ * immediately following a successful @prepare() fails OR if @prepare()
+ * itself fails. @complete() cannot fail.
+ *
+ * @suspend: Executed before putting the system into a sleep state in which the
+ * contents of main memory are preserved. Quiesce the device, put it into
+ * a low power state appropriate for the upcoming system state (such as
+ * PCI_D3hot), and enable wakeup events as appropriate.
+ *
+ * @resume: Executed after waking the system up from a sleep state in which the
+ * contents of main memory were preserved. Put the device into the
+ * appropriate state, according to the information saved in memory by the
+ * preceding @suspend(). The driver starts working again, responding to
+ * hardware events and software requests. The hardware may have gone
+ * through a power-off reset, or it may have maintained state from the
+ * previous suspend() which the driver may rely on while resuming. On most
+ * platforms, there are no restrictions on availability of resources like
+ * clocks during @resume().
+ *
+ * @freeze: Hibernation-specific, executed before creating a hibernation image.
+ * Quiesce operations so that a consistent image can be created, but do NOT
+ * otherwise put the device into a low power device state and do NOT emit
+ * system wakeup events. Save in main memory the device settings to be
+ * used by @restore() during the subsequent resume from hibernation.
+ *
+ * @thaw: Hibernation-specific, executed after creating a hibernation image.
+ * Undo the changes made by the preceding @freeze(), so the device can be
+ * operated in the same was as immediately before the call to @freeze().
+ *
+ * @poweroff: Hibernation-specific, executed after saving a hibernation image.
+ * Quiesce the device, put it into a low power state appropriate for the
+ * upcoming system state (such as PCI_D3hot), and enable wakeup events as
+ * appropriate.
+ *
+ * @quiesce: Hibernation-specific, executed after loading a hibernation image
+ * and before restoring the contents of main memory from it. Quiesce
+ * operations so that the contents of main memory can be restored from the
+ * image in a consistent way, but do NOT otherwise put the device into a
+ * low power state and do NOT emit system wakeup events. Do NOT save any
+ * device settings in main memory.
+ *
+ * @restore: Hibernation-specific, executed after restoring the contents of main
+ * memory from a hibernation image. Driver starts working again,
+ * responding to hardware events and software requests. Do NOT make ANY
+ * assumptions about the hardware state right prior to @restore(). On most
+ * platforms, there are no restrictions on availability of resources like
+ * clocks during @restore().
+ *
+ * @recover: Hibernation-specific, executed after a failing creation of a
+ * hibernation image OR after a failing attempt to restore the contents of
+ * main memory from such an image. Undo the changes made by the preceding
+ * @freeze() or @quiesce(), so the device can be operated in the same way
+ * as immediately before the failing transition.
+ *
+ * struct pm_ops is also used for defining driver PM operations to be carried
+ * out with interrupts disabled. In this case, however, there is only one
+ * active CPU while the operations are being performed, so they are executed by
+ * the PM core in a more straightforward way. In particular, the failure of
+ * @prepare() carried out with interrupts disabled causes the entire PM
+ * transition to fail, regardless of the error code returned by it.
+ */
+
+struct pm_ops {
+#ifdef CONFIG_PM_SLEEP
+ int (*prepare)(struct device *dev);
+ void (*complete)(struct device *dev);
+#endif
+#ifdef CONFIG_SUSPEND
+ int (*suspend)(struct device *dev);
+ int (*resume)(struct device *dev);
+#endif
+#ifdef CONFIG_HIBERNATION
+ int (*freeze)(struct device *dev);
+ int (*thaw)(struct device *dev);
+ int (*poweroff)(struct device *dev);
+ int (*quiesce)(struct device *dev);
+ int (*restore)(struct device *dev);
+ int (*recover)(struct device *dev);
+#endif
+};
+
+/**
+ * PM_EVENT_ messages
+ *
+ * The following PM_EVENT_ messages are defined for the internal use of the PM
+ * core, in order to provide a mechanism allowing the high level suspend and
+ * hibernation code to convey the necessary information to the device PM core
+ * code:
+ *
+ * ON No transition.
+ *
+ * FREEZE System is going to hibernate, call ->prepare() and ->freeze()
+ * for all devices.
+ *
+ * SUSPEND System is going to suspend, call ->prepare() and ->suspend()
+ * for all devices.
+ *
+ * HIBERNATE Hibernation image has been saved, call ->prepare() and
+ * ->poweroff() for all devices.
+ *
+ * QUIESCE Contents of main memory are going to be restored from a (loaded)
+ * hibernation image, call ->prepare() and ->quiesce() for all
+ * devices.
+ *
+ * RESUME System is resuming, call ->resume() and ->complete() for all
+ * devices.
+ *
+ * THAW Hibernation image has been created, call ->thaw() and
+ * ->complete() for all devices.
+ *
+ * RESTORE Contents of main memory have been restored from a hibernation
+ * image, call ->restore() and ->complete() for all devices.
+ *
+ * RECOVER Creation of a hibernation image or restoration of the main
+ * memory contents from a hibernation image has failed, call
+ * ->recover() and ->complete() for all devices.
+ */
+
+typedef struct pm_message {
+ int event;
+} pm_message_t;
+
+#define PM_EVENT_ON 0x0000
+#define PM_EVENT_FREEZE 0x0001
+#define PM_EVENT_SUSPEND 0x0002
+#define PM_EVENT_HIBERNATE 0x0004
+#define PM_EVENT_QUIESCE 0x0008
+#define PM_EVENT_RESUME 0x0010
+#define PM_EVENT_THAW 0x0020
+#define PM_EVENT_RESTORE 0x0040
+#define PM_EVENT_RECOVER 0x0080
+
+#define PM_EVENT_SLEEP (PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
+
+#define PMSG_FREEZE ((struct pm_message){ .event = PM_EVENT_FREEZE, })
+#define PMSG_QUIESCE ((struct pm_message){ .event = PM_EVENT_QUIESCE, })
+#define PMSG_SUSPEND ((struct pm_message){ .event = PM_EVENT_SUSPEND, })
+#define PMSG_HIBERNATE ((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
+#define PMSG_RESUME ((struct pm_message){ .event = PM_EVENT_RESUME, })
+#define PMSG_THAW ((struct pm_message){ .event = PM_EVENT_THAW, })
+#define PMSG_RESTORE ((struct pm_message){ .event = PM_EVENT_RESTORE, })
+#define PMSG_RECOVER ((struct pm_message){ .event = PM_EVENT_RECOVER, })
+#define PMSG_ON ((struct pm_message){ .event = PM_EVENT_ON, })
+
+/**
+ * Device power management states
+ *
+ * These state labels are used internally by the PM core to indicate the current
+ * status of a device with respect to the PM core operations.
+ *
+ * DPM_ON Device is regarded as operational.
+ *
+ * DPM_SUSPENDING Device is currently being suspended.
+ *
+ * DPM_OFF Device is regarded as suspended.
+ */
+
+enum dpm_state {
+ DPM_ON,
+ DPM_SUSPENDING,
+ DPM_OFF,
+};
+
+struct dev_pm_info {
+ pm_message_t power_state;
+ unsigned can_wakeup:1;
+ enum dpm_state status:2; /* Owned by the PM core */
+#ifdef CONFIG_PM_SLEEP
+ unsigned should_wakeup:1;
+ struct list_head entry;
+#endif
+};
+
+/*
+ * The PM_EVENT_ messages are also used by drivers implementing the legacy
+ * suspend framework, based on the ->suspend() and ->resume() callbacks common
+ * for suspend and hibernation transitions, according to the rules below.
+ */
+
+/* Necessary, because several drivers use PM_EVENT_PRETHAW */
+#define PM_EVENT_PRETHAW PM_EVENT_QUIESCE
+
+/*
* One transition is triggered by resume(), after a suspend() call; the
* message is implicit:
*
@@ -166,35 +364,11 @@ typedef struct pm_message {
* or from system low-power states such as standby or suspend-to-RAM.
*/
-#define PM_EVENT_ON 0
-#define PM_EVENT_FREEZE 1
-#define PM_EVENT_SUSPEND 2
-#define PM_EVENT_HIBERNATE 4
-#define PM_EVENT_PRETHAW 8
-
-#define PM_EVENT_SLEEP (PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
-
-#define PMSG_FREEZE ((struct pm_message){ .event = PM_EVENT_FREEZE, })
-#define PMSG_PRETHAW ((struct pm_message){ .event = PM_EVENT_PRETHAW, })
-#define PMSG_SUSPEND ((struct pm_message){ .event = PM_EVENT_SUSPEND, })
-#define PMSG_HIBERNATE ((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
-#define PMSG_ON ((struct pm_message){ .event = PM_EVENT_ON, })
-
-struct dev_pm_info {
- pm_message_t power_state;
- unsigned can_wakeup:1;
- bool sleeping:1; /* Owned by the PM core */
-#ifdef CONFIG_PM_SLEEP
- unsigned should_wakeup:1;
- struct list_head entry;
-#endif
-};
+#ifdef CONFIG_PM_SLEEP
+extern void device_power_up(pm_message_t state);
+extern void device_resume(pm_message_t state);
extern int device_power_down(pm_message_t state);
-extern void device_power_up(void);
-extern void device_resume(void);
-
-#ifdef CONFIG_PM_SLEEP
extern int device_suspend(pm_message_t state);
extern int device_prepare_suspend(pm_message_t state);
Index: linux-2.6/drivers/base/power/main.c
===================================================================
--- linux-2.6.orig/drivers/base/power/main.c
+++ linux-2.6/drivers/base/power/main.c
@@ -71,22 +71,30 @@ int device_pm_add(struct device *dev)
dev->bus ? dev->bus->name : "No Bus",
kobject_name(&dev->kobj));
mutex_lock(&dpm_list_mtx);
- if ((dev->parent && dev->parent->power.sleeping) || all_sleeping) {
- if (dev->parent->power.sleeping)
- dev_warn(dev,
- "parent %s is sleeping, will not add\n",
+ if (all_sleeping) {
+ dev_warn(dev, "all devices are sleeping, will not add\n");
+ goto Refuse;
+ }
+ if (dev->parent)
+ switch (dev->parent->power.status) {
+ case DPM_OFF:
+ dev_warn(dev, "parent %s is sleeping, will not add\n",
dev->parent->bus_id);
- else
- dev_warn(dev, "devices are sleeping, will not add\n");
- WARN_ON(true);
- error = -EBUSY;
- } else {
- error = dpm_sysfs_add(dev);
- if (!error)
- list_add_tail(&dev->power.entry, &dpm_active);
- }
+ goto Refuse;
+ case DPM_SUSPENDING:
+ dev->parent->power.status = DPM_ON;
+ break;
+ }
+ error = dpm_sysfs_add(dev);
+ if (!error)
+ list_add_tail(&dev->power.entry, &dpm_active);
+ End:
mutex_unlock(&dpm_list_mtx);
return error;
+ Refuse:
+ WARN_ON(true);
+ error = -EBUSY;
+ goto End;
}
/**
@@ -124,26 +132,135 @@ void device_pm_schedule_removal(struct d
}
EXPORT_SYMBOL_GPL(device_pm_schedule_removal);
+/**
+ * pm_op - execute the PM operation appropiate for given PM event
+ * @dev: Device.
+ * @ops: PM operations to choose from.
+ * @state: PM event message.
+ */
+static int pm_op(struct device *dev, struct pm_ops *ops, pm_message_t state)
+{
+ int error = 0;
+
+ switch (state.event) {
+#ifdef CONFIG_SUSPEND
+ case PM_EVENT_SUSPEND:
+ if (ops->suspend) {
+ error = ops->suspend(dev);
+ suspend_report_result(ops->suspend, error);
+ }
+ break;
+ case PM_EVENT_RESUME:
+ if (ops->resume) {
+ error = ops->resume(dev);
+ suspend_report_result(ops->resume, error);
+ }
+ break;
+#endif /* CONFIG_SUSPEND */
+#ifdef CONFIG_HIBERNATION
+ case PM_EVENT_FREEZE:
+ if (ops->freeze) {
+ error = ops->freeze(dev);
+ suspend_report_result(ops->freeze, error);
+ }
+ break;
+ case PM_EVENT_QUIESCE:
+ if (ops->quiesce) {
+ error = ops->quiesce(dev);
+ suspend_report_result(ops->quiesce, error);
+ }
+ break;
+ case PM_EVENT_HIBERNATE:
+ if (ops->poweroff) {
+ error = ops->poweroff(dev);
+ suspend_report_result(ops->poweroff, error);
+ }
+ break;
+ case PM_EVENT_THAW:
+ if (ops->thaw) {
+ error = ops->thaw(dev);
+ suspend_report_result(ops->thaw, error);
+ }
+ break;
+ case PM_EVENT_RESTORE:
+ if (ops->restore) {
+ error = ops->restore(dev);
+ suspend_report_result(ops->restore, error);
+ }
+ break;
+ case PM_EVENT_RECOVER:
+ if (ops->recover) {
+ error = ops->recover(dev);
+ suspend_report_result(ops->recover, error);
+ }
+ break;
+#endif /* CONFIG_HIBERNATION */
+ default:
+ error = -EINVAL;
+ }
+ return error;
+}
+
+static char *pm_verb(int event)
+{
+ switch (event) {
+ case PM_EVENT_SUSPEND:
+ return "suspend";
+ case PM_EVENT_RESUME:
+ return "resume";
+ case PM_EVENT_FREEZE:
+ return "freeze";
+ case PM_EVENT_QUIESCE:
+ return "quiesce";
+ case PM_EVENT_HIBERNATE:
+ return "hibernate";
+ case PM_EVENT_THAW:
+ return "thaw";
+ case PM_EVENT_RESTORE:
+ return "restore";
+ default:
+ return "(unknown PM event)";
+ }
+}
+
+static void pm_dev_dbg(struct device *dev, pm_message_t state, char *info)
+{
+ dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
+ ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
+ ", may wakeup" : "");
+}
+
/*------------------------- Resume routines -------------------------*/
/**
- * resume_device_early - Power on one device (early resume).
+ * resume_device_noirq - Power on one device (early resume).
* @dev: Device.
+ * @state: Operation to carry out.
*
* Must be called with interrupts disabled.
*/
-static int resume_device_early(struct device *dev)
+static int resume_device_noirq(struct device *dev, pm_message_t state)
{
int error = 0;
TRACE_DEVICE(dev);
TRACE_RESUME(0);
- if (dev->bus && dev->bus->resume_early) {
- dev_dbg(dev, "EARLY resume\n");
+ if (!dev->bus)
+ goto End;
+
+ if (dev->bus->pm_noirq) {
+ struct pm_ops *ops = dev->bus->pm_noirq;
+
+ pm_dev_dbg(dev, state, "EARLY ");
+ error = pm_op(dev, ops, state);
+ if (ops->complete)
+ ops->complete(dev);
+ } else if (dev->bus->resume_early) {
+ pm_dev_dbg(dev, state, "legacy EARLY ");
error = dev->bus->resume_early(dev);
}
-
+ End:
TRACE_RESUME(error);
return error;
}
@@ -158,7 +275,7 @@ static int resume_device_early(struct de
*
* Must be called with interrupts disabled and only one CPU running.
*/
-static void dpm_power_up(void)
+static void dpm_power_up(pm_message_t state)
{
while (!list_empty(&dpm_off_irq)) {
@@ -166,7 +283,7 @@ static void dpm_power_up(void)
struct device *dev = to_device(entry);
list_move_tail(entry, &dpm_off);
- resume_device_early(dev);
+ resume_device_noirq(dev, state);
}
}
@@ -178,19 +295,46 @@ static void dpm_power_up(void)
*
* Must be called with interrupts disabled.
*/
-void device_power_up(void)
+void device_power_up(pm_message_t state)
{
sysdev_resume();
- dpm_power_up();
+ dpm_power_up(state);
}
EXPORT_SYMBOL_GPL(device_power_up);
/**
+ * complete_device - Complete a PM transition for given device
+ * @dev: Device.
+ * @state: Power transition we are completing.
+ */
+static void complete_device(struct device *dev, pm_message_t state)
+{
+ down(&dev->sem);
+
+ if (dev->bus && dev->bus->pm && dev->bus->pm->complete) {
+ pm_dev_dbg(dev, state, "completing ");
+ dev->bus->pm->complete(dev);
+ }
+
+ if (dev->type && dev->type->pm && dev->type->pm->complete) {
+ pm_dev_dbg(dev, state, "completing type ");
+ dev->type->pm->complete(dev);
+ }
+
+ if (dev->class && dev->class->pm && dev->class->pm->complete) {
+ pm_dev_dbg(dev, state, "completing class ");
+ dev->class->pm->complete(dev);
+ }
+
+ up(&dev->sem);
+}
+
+/**
* resume_device - Restore state for one device.
* @dev: Device.
- *
+ * @state: Operation to carry out.
*/
-static int resume_device(struct device *dev)
+static int resume_device(struct device *dev, pm_message_t state)
{
int error = 0;
@@ -199,21 +343,40 @@ static int resume_device(struct device *
down(&dev->sem);
- if (dev->bus && dev->bus->resume) {
- dev_dbg(dev,"resuming\n");
- error = dev->bus->resume(dev);
+ if (dev->bus) {
+ if (dev->bus->pm) {
+ pm_dev_dbg(dev, state, "");
+ error = pm_op(dev, dev->bus->pm, state);
+ } else if (dev->bus->resume) {
+ pm_dev_dbg(dev, state, "legacy ");
+ error = dev->bus->resume(dev);
+ }
+ if (error)
+ goto End;
}
- if (!error && dev->type && dev->type->resume) {
- dev_dbg(dev,"resuming\n");
- error = dev->type->resume(dev);
+ if (dev->type) {
+ if (dev->type->pm) {
+ pm_dev_dbg(dev, state, "type ");
+ error = pm_op(dev, dev->type->pm, state);
+ } else if (dev->type->resume) {
+ pm_dev_dbg(dev, state, "legacy type ");
+ error = dev->type->resume(dev);
+ }
+ if (error)
+ goto End;
}
- if (!error && dev->class && dev->class->resume) {
- dev_dbg(dev,"class resume\n");
- error = dev->class->resume(dev);
+ if (dev->class) {
+ if (dev->class->pm) {
+ pm_dev_dbg(dev, state, "class ");
+ error = pm_op(dev, dev->class->pm, state);
+ } else if (dev->class->resume) {
+ pm_dev_dbg(dev, state, "legacy class ");
+ error = dev->class->resume(dev);
+ }
}
-
+ End:
up(&dev->sem);
TRACE_RESUME(error);
@@ -228,9 +391,9 @@ static int resume_device(struct device *
* went through the early resume.
*
* Take devices from the dpm_off_list, resume them,
- * and put them on the dpm_locked list.
+ * and put them on the dpm_active list.
*/
-static void dpm_resume(void)
+static void dpm_resume(pm_message_t state)
{
mutex_lock(&dpm_list_mtx);
all_sleeping = false;
@@ -239,9 +402,10 @@ static void dpm_resume(void)
struct device *dev = to_device(entry);
list_move_tail(entry, &dpm_active);
- dev->power.sleeping = false;
+ dev->power.status = DPM_ON;
mutex_unlock(&dpm_list_mtx);
- resume_device(dev);
+ resume_device(dev, state);
+ complete_device(dev, state);
mutex_lock(&dpm_list_mtx);
}
mutex_unlock(&dpm_list_mtx);
@@ -269,14 +433,15 @@ static void unregister_dropped_devices(v
/**
* device_resume - Restore state of each device in system.
+ * @state: Operation to carry out.
*
* Resume all the devices, unlock them all, and allow new
* devices to be registered once again.
*/
-void device_resume(void)
+void device_resume(pm_message_t state)
{
might_sleep();
- dpm_resume();
+ dpm_resume(state);
unregister_dropped_devices();
}
EXPORT_SYMBOL_GPL(device_resume);
@@ -284,37 +449,51 @@ EXPORT_SYMBOL_GPL(device_resume);
/*------------------------- Suspend routines -------------------------*/
-static inline char *suspend_verb(u32 event)
+/**
+ * resume_event - return a PM message representing the resume event
+ * corresponding to given sleep state.
+ * @sleep_state - PM message representing a sleep state
+ */
+static pm_message_t resume_event(pm_message_t sleep_state)
{
- switch (event) {
- case PM_EVENT_SUSPEND: return "suspend";
- case PM_EVENT_FREEZE: return "freeze";
- case PM_EVENT_PRETHAW: return "prethaw";
- default: return "(unknown suspend event)";
+ switch (sleep_state.event) {
+ case PM_EVENT_SUSPEND:
+ return PMSG_RESUME;
+ case PM_EVENT_FREEZE:
+ case PM_EVENT_QUIESCE:
+ return PMSG_RECOVER;
+ case PM_EVENT_HIBERNATE:
+ return PMSG_RESTORE;
}
-}
-
-static void
-suspend_device_dbg(struct device *dev, pm_message_t state, char *info)
-{
- dev_dbg(dev, "%s%s%s\n", info, suspend_verb(state.event),
- ((state.event == PM_EVENT_SUSPEND) && device_may_wakeup(dev)) ?
- ", may wakeup" : "");
+ return PMSG_ON;
}
/**
- * suspend_device_late - Shut down one device (late suspend).
+ * suspend_device_noirq - Shut down one device (late suspend).
* @dev: Device.
- * @state: Power state device is entering.
+ * @state: PM message representing the operation to perform.
*
* This is called with interrupts off and only a single CPU running.
*/
-static int suspend_device_late(struct device *dev, pm_message_t state)
+static int suspend_device_noirq(struct device *dev, pm_message_t state)
{
int error = 0;
- if (dev->bus && dev->bus->suspend_late) {
- suspend_device_dbg(dev, state, "LATE ");
+ if (!dev->bus)
+ return 0;
+
+ if (dev->bus->pm_noirq) {
+ struct pm_ops *ops = dev->bus->pm_noirq;
+
+ pm_dev_dbg(dev, state, "LATE ");
+ if (ops->prepare)
+ error = ops->prepare(dev);
+ if (!error)
+ error = pm_op(dev, ops, state);
+ if (error && ops->complete)
+ ops->complete(dev);
+ } else if (dev->bus->suspend_late) {
+ pm_dev_dbg(dev, state, "legacy LATE ");
error = dev->bus->suspend_late(dev, state);
suspend_report_result(dev->bus->suspend_late, error);
}
@@ -323,7 +502,7 @@ static int suspend_device_late(struct de
/**
* device_power_down - Shut down special devices.
- * @state: Power state to enter.
+ * @state: PM message representing the operation to perform.
*
* Power down devices that require interrupts to be disabled
* and move them from the dpm_off list to the dpm_off_irq list.
@@ -339,7 +518,7 @@ int device_power_down(pm_message_t state
struct list_head *entry = dpm_off.prev;
struct device *dev = to_device(entry);
- error = suspend_device_late(dev, state);
+ error = suspend_device_noirq(dev, state);
if (error) {
printk(KERN_ERR "Could not power down device %s: "
"error %d\n",
@@ -353,12 +532,50 @@ int device_power_down(pm_message_t state
if (!error)
error = sysdev_suspend(state);
if (error)
- dpm_power_up();
+ dpm_power_up(resume_event(state));
return error;
}
EXPORT_SYMBOL_GPL(device_power_down);
/**
+ * prepare_device - Execute the ->prepare() callback(s) for given device.
+ * @dev: Device.
+ * @state: PM operation we are preparing for.
+ */
+static int prepare_device(struct device *dev, pm_message_t state)
+{
+ int error = 0;
+
+ down(&dev->sem);
+
+ if (dev->bus && dev->bus->pm && dev->bus->pm->prepare) {
+ pm_dev_dbg(dev, state, "preparing ");
+ error = dev->bus->pm->prepare(dev);
+ suspend_report_result(dev->bus->pm->prepare, error);
+ if (error)
+ goto End;
+ }
+
+ if (dev->type && dev->type->pm && dev->type->pm->prepare) {
+ pm_dev_dbg(dev, state, "preparing type ");
+ error = dev->type->pm->prepare(dev);
+ suspend_report_result(dev->type->pm->prepare, error);
+ if (error)
+ goto End;
+ }
+
+ if (dev->class && dev->class->pm && dev->class->pm->prepare) {
+ pm_dev_dbg(dev, state, "preparing class ");
+ error = dev->class->pm->prepare(dev);
+ suspend_report_result(dev->class->pm->prepare, error);
+ }
+ End:
+ up(&dev->sem);
+
+ return error;
+}
+
+/**
* suspend_device - Save state of one device.
* @dev: Device.
* @state: Power state device is entering.
@@ -369,29 +586,43 @@ static int suspend_device(struct device
down(&dev->sem);
- if (dev->power.power_state.event) {
- dev_dbg(dev, "PM: suspend %d-->%d\n",
- dev->power.power_state.event, state.event);
- }
-
- if (dev->class && dev->class->suspend) {
- suspend_device_dbg(dev, state, "class ");
- error = dev->class->suspend(dev, state);
- suspend_report_result(dev->class->suspend, error);
+ if (dev->class) {
+ if (dev->class->pm) {
+ pm_dev_dbg(dev, state, "class ");
+ error = pm_op(dev, dev->class->pm, state);
+ } else if (dev->class->suspend) {
+ pm_dev_dbg(dev, state, "legacy class ");
+ error = dev->class->suspend(dev, state);
+ suspend_report_result(dev->class->suspend, error);
+ }
+ if (error)
+ goto End;
}
- if (!error && dev->type && dev->type->suspend) {
- suspend_device_dbg(dev, state, "type ");
- error = dev->type->suspend(dev, state);
- suspend_report_result(dev->type->suspend, error);
+ if (dev->type) {
+ if (dev->type->pm) {
+ pm_dev_dbg(dev, state, "type ");
+ error = pm_op(dev, dev->type->pm, state);
+ } else if (dev->type->suspend) {
+ pm_dev_dbg(dev, state, "legacy type ");
+ error = dev->type->suspend(dev, state);
+ suspend_report_result(dev->type->suspend, error);
+ }
+ if (error)
+ goto End;
}
- if (!error && dev->bus && dev->bus->suspend) {
- suspend_device_dbg(dev, state, "");
- error = dev->bus->suspend(dev, state);
- suspend_report_result(dev->bus->suspend, error);
+ if (dev->bus) {
+ if (dev->bus->pm) {
+ pm_dev_dbg(dev, state, "");
+ error = pm_op(dev, dev->bus->pm, state);
+ } else if (dev->bus->suspend) {
+ pm_dev_dbg(dev, state, "legacy ");
+ error = dev->bus->suspend(dev, state);
+ suspend_report_result(dev->bus->suspend, error);
+ }
}
-
+ End:
up(&dev->sem);
return error;
@@ -401,56 +632,70 @@ static int suspend_device(struct device
* dpm_suspend - Suspend every device.
* @state: Power state to put each device in.
*
- * Walk the dpm_locked list. Suspend each device and move it
+ * Walk the dpm_active list. Suspend each device and move it
* to the dpm_off list.
- *
- * (For historical reasons, if it returns -EAGAIN, that used to mean
- * that the device would be called again with interrupts disabled.
- * These days, we use the "suspend_late()" callback for that, so we
- * print a warning and consider it an error).
*/
static int dpm_suspend(pm_message_t state)
{
- int error = 0;
-
mutex_lock(&dpm_list_mtx);
while (!list_empty(&dpm_active)) {
struct list_head *entry = dpm_active.prev;
struct device *dev = to_device(entry);
+ int error;
+
+ WARN_ON(dev->parent && dev->parent->power.status == DPM_OFF);
+ dev->power.status = DPM_SUSPENDING;
+ mutex_unlock(&dpm_list_mtx);
+
+ error = prepare_device(dev, state);
- WARN_ON(dev->parent && dev->parent->power.sleeping);
+ mutex_lock(&dpm_list_mtx);
+ if (error == -EAGAIN)
+ dev->power.status = DPM_ON;
+ else if(error)
+ goto Error;
+ if (dev->power.status == DPM_ON) {
+ /*
+ * prepare_device() returned -EAGAIN or a child was
+ * added during it
+ */
+ mutex_unlock(&dpm_list_mtx);
+
+ complete_device(dev, resume_event(state));
- dev->power.sleeping = true;
+ mutex_lock(&dpm_list_mtx);
+ continue;
+ }
+ dev->power.status = DPM_OFF;
mutex_unlock(&dpm_list_mtx);
+
error = suspend_device(dev, state);
+
mutex_lock(&dpm_list_mtx);
- if (error) {
- printk(KERN_ERR "Could not suspend device %s: "
- "error %d%s\n",
- kobject_name(&dev->kobj),
- error,
- (error == -EAGAIN ?
- " (please convert to suspend_late)" :
- ""));
- dev->power.sleeping = false;
- break;
+ if (!error) {
+ if (!list_empty(&dev->power.entry))
+ list_move(&dev->power.entry, &dpm_off);
+ continue;
}
- if (!list_empty(&dev->power.entry))
- list_move(&dev->power.entry, &dpm_off);
+ Error:
+ printk(KERN_ERR "Could not suspend device %s: error %d\n",
+ kobject_name(&dev->kobj), error);
+ dev->power.status = DPM_ON;
+ mutex_unlock(&dpm_list_mtx);
+
+ complete_device(dev, resume_event(state));
+ return error;
}
- if (!error)
- all_sleeping = true;
+ all_sleeping = true;
mutex_unlock(&dpm_list_mtx);
-
- return error;
+ return 0;
}
/**
* device_suspend - Save state and stop all devices in system.
* @state: new power management state
*
- * Prevent new devices from being registered, then lock all devices
- * and suspend them.
+ * Prepare and suspend all devices.
*/
int device_suspend(pm_message_t state)
{
@@ -459,7 +704,7 @@ int device_suspend(pm_message_t state)
might_sleep();
error = dpm_suspend(state);
if (error)
- device_resume();
+ device_resume(resume_event(state));
return error;
}
EXPORT_SYMBOL_GPL(device_suspend);
Index: linux-2.6/include/linux/device.h
===================================================================
--- linux-2.6.orig/include/linux/device.h
+++ linux-2.6/include/linux/device.h
@@ -69,6 +69,9 @@ struct bus_type {
int (*resume_early)(struct device *dev);
int (*resume)(struct device *dev);
+ struct pm_ops *pm;
+ struct pm_ops *pm_noirq;
+
struct bus_type_private *p;
};
@@ -202,6 +205,8 @@ struct class {
int (*suspend)(struct device *dev, pm_message_t state);
int (*resume)(struct device *dev);
+
+ struct pm_ops *pm;
};
extern int __must_check class_register(struct class *class);
@@ -345,8 +350,11 @@ struct device_type {
struct attribute_group **groups;
int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
void (*release)(struct device *dev);
+
int (*suspend)(struct device *dev, pm_message_t state);
int (*resume)(struct device *dev);
+
+ struct pm_ops *pm;
};
/* interface for exporting device attributes */
Index: linux-2.6/kernel/power/disk.c
===================================================================
--- linux-2.6.orig/kernel/power/disk.c
+++ linux-2.6/kernel/power/disk.c
@@ -224,7 +224,7 @@ static int create_image(int platform_mod
/* NOTE: device_power_up() is just a resume() for devices
* that suspended with irqs off ... no overall powerup.
*/
- device_power_up();
+ device_power_up(in_suspend ? PMSG_RECOVER : PMSG_RESTORE);
Enable_irqs:
local_irq_enable();
return error;
@@ -280,7 +280,7 @@ int hibernation_snapshot(int platform_mo
Finish:
platform_finish(platform_mode);
Resume_devices:
- device_resume();
+ device_resume(in_suspend ? PMSG_RECOVER : PMSG_RESTORE);
Resume_console:
resume_console();
Close:
@@ -301,7 +301,7 @@ static int resume_target_kernel(void)
int error;
local_irq_disable();
- error = device_power_down(PMSG_PRETHAW);
+ error = device_power_down(PMSG_QUIESCE);
if (error) {
printk(KERN_ERR "PM: Some devices failed to power down, "
"aborting resume\n");
@@ -329,7 +329,7 @@ static int resume_target_kernel(void)
swsusp_free();
restore_processor_state();
touch_softlockup_watchdog();
- device_power_up();
+ device_power_up(PMSG_THAW);
Enable_irqs:
local_irq_enable();
return error;
@@ -350,7 +350,7 @@ int hibernation_restore(int platform_mod
pm_prepare_console();
suspend_console();
- error = device_suspend(PMSG_PRETHAW);
+ error = device_suspend(PMSG_QUIESCE);
if (error)
goto Finish;
@@ -362,7 +362,7 @@ int hibernation_restore(int platform_mod
enable_nonboot_cpus();
}
platform_restore_cleanup(platform_mode);
- device_resume();
+ device_resume(PMSG_RECOVER);
Finish:
resume_console();
pm_restore_console();
@@ -419,7 +419,7 @@ int hibernation_platform_enter(void)
Finish:
hibernation_ops->finish();
Resume_devices:
- device_resume();
+ device_resume(PMSG_RESTORE);
Resume_console:
resume_console();
Close:
Index: linux-2.6/kernel/power/main.c
===================================================================
--- linux-2.6.orig/kernel/power/main.c
+++ linux-2.6/kernel/power/main.c
@@ -239,7 +239,7 @@ static int suspend_enter(suspend_state_t
if (!suspend_test(TEST_CORE))
error = suspend_ops->enter(state);
- device_power_up();
+ device_power_up(PMSG_RESUME);
Done:
arch_suspend_enable_irqs();
BUG_ON(irqs_disabled());
@@ -291,7 +291,7 @@ int suspend_devices_and_enter(suspend_st
if (suspend_ops->finish)
suspend_ops->finish();
Resume_devices:
- device_resume();
+ device_resume(PMSG_RESUME);
Resume_console:
resume_console();
Close:
Index: linux-2.6/arch/x86/kernel/apm_32.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/apm_32.c
+++ linux-2.6/arch/x86/kernel/apm_32.c
@@ -1221,9 +1221,9 @@ static int suspend(int vetoable)
if (err != APM_SUCCESS)
apm_error("suspend", err);
err = (err == APM_SUCCESS) ? 0 : -EIO;
- device_power_up();
+ device_power_up(PMSG_RESUME);
local_irq_enable();
- device_resume();
+ device_resume(PMSG_RESUME);
pm_send_all(PM_RESUME, (void *)0);
queue_event(APM_NORMAL_RESUME, NULL);
out:
--
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