5 files changed, 130 insertions, 36 deletions

diff --git a/drivers/base/power/resume.c b/drivers/base/power/resume.c
index 826093ef4c7e..48e3d49d7b65 100644
--- a/drivers/base/power/resume.c
+++ b/drivers/base/power/resume.c
@@ -38,13 +38,35 @@ int resume_device(struct device * dev)
                 dev_dbg(dev,"resuming\n");
                 error = dev->bus->resume(dev);
         }
+        if (dev->class && dev->class->resume) {
+                dev_dbg(dev,"class resume\n");
+                error = dev->class->resume(dev);
+        }
         up(&dev->sem);
         TRACE_RESUME(error);
         return error;
 }
 
 
+static int resume_device_early(struct device * dev)
+{
+        int error = 0;
 
+        TRACE_DEVICE(dev);
+        TRACE_RESUME(0);
+        if (dev->bus && dev->bus->resume_early) {
+                dev_dbg(dev,"EARLY resume\n");
+                error = dev->bus->resume_early(dev);
+        }
+        TRACE_RESUME(error);
+        return error;
+}
+
+/*
+ * Resume the devices that have either not gone through
+ * the late suspend, or that did go through it but also
+ * went through the early resume
+ */
 void dpm_resume(void)
 {
         down(&dpm_list_sem);
@@ -99,10 +121,8 @@ void dpm_power_up(void)
                 struct list_head * entry = dpm_off_irq.next;
                 struct device * dev = to_device(entry);
 
-                get_device(dev);
-                list_move_tail(entry, &dpm_active);
-                resume_device(dev);
-                put_device(dev);
+                list_move_tail(entry, &dpm_off);
+                resume_device_early(dev);
         }
 }
 
diff --git a/drivers/base/power/suspend.c b/drivers/base/power/suspend.c
index 69509e02f703..10e8032aee1a 100644
--- a/drivers/base/power/suspend.c
+++ b/drivers/base/power/suspend.c
@@ -65,7 +65,19 @@ int suspend_device(struct device * dev, pm_message_t state)
 
         dev->power.prev_state = dev->power.power_state;
 
-        if (dev->bus && dev->bus->suspend && !dev->power.power_state.event) {
+        if (dev->class && dev->class->suspend && !dev->power.power_state.event) {
+                dev_dbg(dev, "class %s%s\n",
+                        suspend_verb(state.event),
+                        ((state.event == PM_EVENT_SUSPEND)
+                                        && device_may_wakeup(dev))
+                                ? ", may wakeup"
+                                : ""
+                        );
+                error = dev->class->suspend(dev, state);
+                suspend_report_result(dev->class->suspend, error);
+        }
+
+        if (!error && dev->bus && dev->bus->suspend && !dev->power.power_state.event) {
                 dev_dbg(dev, "%s%s\n",
                         suspend_verb(state.event),
                         ((state.event == PM_EVENT_SUSPEND)
@@ -81,15 +93,74 @@ int suspend_device(struct device * dev, pm_message_t state)
 }
 
 
+/*
+ * This is called with interrupts off, only a single CPU
+ * running. We can't do down() on a semaphore (and we don't
+ * need the protection)
+ */
+static int suspend_device_late(struct device *dev, pm_message_t state)
+{
+        int error = 0;
+
+        if (dev->power.power_state.event) {
+                dev_dbg(dev, "PM: suspend_late %d-->%d\n",
+                        dev->power.power_state.event, state.event);
+        }
+
+        if (dev->bus && dev->bus->suspend_late && !dev->power.power_state.event) {
+                dev_dbg(dev, "LATE %s%s\n",
+                        suspend_verb(state.event),
+                        ((state.event == PM_EVENT_SUSPEND)
+                                        && device_may_wakeup(dev))
+                                ? ", may wakeup"
+                                : ""
+                        );
+                error = dev->bus->suspend_late(dev, state);
+                suspend_report_result(dev->bus->suspend_late, error);
+        }
+        return error;
+}
+
+/**
+ *      device_prepare_suspend - save state and prepare to suspend
+ *
+ *      NOTE! Devices cannot detach at this point - not only do we
+ *      hold the device list semaphores over the whole prepare, but
+ *      the whole point is to do non-invasive preparatory work, not
+ *      the actual suspend.
+ */
+int device_prepare_suspend(pm_message_t state)
+{
+        int error = 0;
+        struct device * dev;
+
+        down(&dpm_sem);
+        down(&dpm_list_sem);
+        list_for_each_entry_reverse(dev, &dpm_active, power.entry) {
+                if (!dev->bus || !dev->bus->suspend_prepare)
+                        continue;
+                error = dev->bus->suspend_prepare(dev, state);
+                if (error)
+                        break;
+        }
+        up(&dpm_list_sem);
+        up(&dpm_sem);
+        return error;
+}
+
 /**
  *      device_suspend - Save state and stop all devices in system.
  *      @state:         Power state to put each device in.
  *
  *      Walk the dpm_active list, call ->suspend() for each device, and move
- *      it to dpm_off.
- *      Check the return value for each. If it returns 0, then we move the
- *      the device to the dpm_off list. If it returns -EAGAIN, we move it to
- *      the dpm_off_irq list. If we get a different error, try and back out.
+ *      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).
+ *
+ *      If we get a different error, try and back out.
  *
  *      If we hit a failure with any of the devices, call device_resume()
  *      above to bring the suspended devices back to life.
@@ -115,39 +186,27 @@ int device_suspend(pm_message_t state)
 
                 /* Check if the device got removed */
                 if (!list_empty(&dev->power.entry)) {
-                        /* Move it to the dpm_off or dpm_off_irq list */
+                        /* Move it to the dpm_off list */
                         if (!error)
                                 list_move(&dev->power.entry, &dpm_off);
-                        else if (error == -EAGAIN) {
-                                list_move(&dev->power.entry, &dpm_off_irq);
-                                error = 0;
-                        }
                 }
                 if (error)
                         printk(KERN_ERR "Could not suspend device %s: "
-                                "error %d\n", kobject_name(&dev->kobj), error);
+                                "error %d%s\n",
+                                kobject_name(&dev->kobj), error,
+                                error == -EAGAIN ? " (please convert to suspend_late)" : "");
                 put_device(dev);
         }
         up(&dpm_list_sem);
-        if (error) {
-                /* we failed... before resuming, bring back devices from
-                 * dpm_off_irq list back to main dpm_off list, we do want
-                 * to call resume() on them, in case they partially suspended
-                 * despite returning -EAGAIN
-                 */
-                while (!list_empty(&dpm_off_irq)) {
-                        struct list_head * entry = dpm_off_irq.next;
-                        list_move(entry, &dpm_off);
-                }
+        if (error)
                 dpm_resume();
-        }
+
         up(&dpm_sem);
         return error;
 }
 
 EXPORT_SYMBOL_GPL(device_suspend);
 
-
 /**
  *      device_power_down - Shut down special devices.
  *      @state:         Power state to enter.
@@ -162,14 +221,17 @@ int device_power_down(pm_message_t state)
         int error = 0;
         struct device * dev;
 
-        list_for_each_entry_reverse(dev, &dpm_off_irq, power.entry) {
-                if ((error = suspend_device(dev, state)))
-                        break;
+        while (!list_empty(&dpm_off)) {
+                struct list_head * entry = dpm_off.prev;
+
+                dev = to_device(entry);
+                error = suspend_device_late(dev, state);
+                if (error)
+                        goto Error;
+                list_move(&dev->power.entry, &dpm_off_irq);
         }
-        if (error)
-                goto Error;
-        if ((error = sysdev_suspend(state)))
-                goto Error;
+
+        error = sysdev_suspend(state);
  Done:
         return error;
  Error:
diff --git a/include/linux/device.h b/include/linux/device.h
index 8a648cd94fa9..b40be6fca6fa 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -51,8 +51,12 @@ struct bus_type {
         int             (*probe)(struct device * dev);
         int             (*remove)(struct device * dev);
         void            (*shutdown)(struct device * dev);
-        int             (*suspend)(struct device * dev, pm_message_t state);
-        int             (*resume)(struct device * dev);
+
+        int (*suspend_prepare)(struct device * dev, pm_message_t state);
+        int (*suspend)(struct device * dev, pm_message_t state);
+        int (*suspend_late)(struct device * dev, pm_message_t state);
+        int (*resume_early)(struct device * dev);
+        int (*resume)(struct device * dev);
 };
 
 extern int bus_register(struct bus_type * bus);
@@ -154,6 +158,9 @@ struct class {
 
         void    (*release)(struct class_device *dev);
         void    (*class_release)(struct class *class);
+
+        int     (*suspend)(struct device *, pm_message_t state);
+        int     (*resume)(struct device *);
 };
 
 extern int class_register(struct class *);
diff --git a/include/linux/pm.h b/include/linux/pm.h
index 658c1b93d5bb..096fb6f754cf 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -190,6 +190,7 @@ extern void device_resume(void);
 extern suspend_disk_method_t pm_disk_mode;
 
 extern int device_suspend(pm_message_t state);
+extern int device_prepare_suspend(pm_message_t state);
 
 #define device_set_wakeup_enable(dev,val) \
         ((dev)->power.should_wakeup = !!(val))
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 6d295c776794..0c3ed6ac938e 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -57,6 +57,10 @@ static int suspend_prepare(suspend_state_t state)
         if (!pm_ops || !pm_ops->enter)
                 return -EPERM;
 
+        error = device_prepare_suspend(PMSG_SUSPEND);
+        if (error)
+                return error;
+
         pm_prepare_console();
 
         disable_nonboot_cpus();