PM / sleep: make PM notifiers called symmetrically

This makes pm notifier PREPARE/POST symmetrical: if PREPARE
fails, we will only undo what ever happened on PREPARE.

It fixes the unbalanced CPU hotplug enable in CPU PM notifier.

Signed-off-by: Lianwei Wang <lianwei.wang@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index fca9254280ee4fad96bc8f2a61772160975c4cd6..126e24caa82edd9f37f1c9a6daa16b5e91d40798 100644 (file)
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -647,7 +647,7 @@ static void power_down(void)
  */
 int hibernate(void)
 {
-       int error;
+       int error, nr_calls = 0;
 
        if (!hibernation_available()) {
                pr_debug("PM: Hibernation not available.\n");
@@ -662,9 +662,11 @@ int hibernate(void)
        }
 
        pm_prepare_console();
-       error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
-       if (error)
+       error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
+       if (error) {
+               nr_calls--;
                goto Exit;
+       }
 
        printk(KERN_INFO "PM: Syncing filesystems ... ");
        sys_sync();
@@ -714,7 +716,7 @@ int hibernate(void)
        /* Don't bother checking whether freezer_test_done is true */
        freezer_test_done = false;
  Exit:
-       pm_notifier_call_chain(PM_POST_HIBERNATION);
+       __pm_notifier_call_chain(PM_POST_HIBERNATION, nr_calls, NULL);
        pm_restore_console();
        atomic_inc(&snapshot_device_available);
  Unlock:
@@ -740,7 +742,7 @@ int hibernate(void)
  */
 static int software_resume(void)
 {
-       int error;
+       int error, nr_calls = 0;
        unsigned int flags;
 
        /*
@@ -827,9 +829,11 @@ static int software_resume(void)
        }
 
        pm_prepare_console();
-       error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
-       if (error)
+       error = __pm_notifier_call_chain(PM_RESTORE_PREPARE, -1, &nr_calls);
+       if (error) {
+               nr_calls--;
                goto Close_Finish;
+       }
 
        pr_debug("PM: Preparing processes for restore.\n");
        error = freeze_processes();
@@ -855,7 +859,7 @@ static int software_resume(void)
        unlock_device_hotplug();
        thaw_processes();
  Finish:
-       pm_notifier_call_chain(PM_POST_RESTORE);
+       __pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
        pm_restore_console();
        atomic_inc(&snapshot_device_available);
        /* For success case, the suspend path will release the lock */

diff --git a/kernel/power/main.c b/kernel/power/main.c
index 27946975eff004f210d563e73218f1fe6d0b9a9e..5ea50b1b7595ba778eaaf90de9c3af51586156af 100644 (file)
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -38,12 +38,19 @@ int unregister_pm_notifier(struct notifier_block *nb)
 }
 EXPORT_SYMBOL_GPL(unregister_pm_notifier);
 
-int pm_notifier_call_chain(unsigned long val)
+int __pm_notifier_call_chain(unsigned long val, int nr_to_call, int *nr_calls)
 {
-       int ret = blocking_notifier_call_chain(&pm_chain_head, val, NULL);
+       int ret;
+
+       ret = __blocking_notifier_call_chain(&pm_chain_head, val, NULL,
+                                               nr_to_call, nr_calls);
 
        return notifier_to_errno(ret);
 }
+int pm_notifier_call_chain(unsigned long val)
+{
+       return __pm_notifier_call_chain(val, -1, NULL);
+}
 
 /* If set, devices may be suspended and resumed asynchronously. */
 int pm_async_enabled = 1;

diff --git a/kernel/power/power.h b/kernel/power/power.h
index efe1b3b17c88d0eb793fa84ceec00e5b31604af4..51f02ecaf12552984db9ab122d4591a8bb6050ec 100644 (file)
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -200,6 +200,8 @@ static inline void suspend_test_finish(const char *label) {}
 
 #ifdef CONFIG_PM_SLEEP
 /* kernel/power/main.c */
+extern int __pm_notifier_call_chain(unsigned long val, int nr_to_call,
+                                   int *nr_calls);
 extern int pm_notifier_call_chain(unsigned long val);
 #endif
 

diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 5b70d64b871e7aac6dd7a81527ab5825d8001e0f..0acab9d7f96f6cfc0d46906a21295c94215295bc 100644 (file)
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -266,16 +266,18 @@ static int suspend_test(int level)
  */
 static int suspend_prepare(suspend_state_t state)
 {
-       int error;
+       int error, nr_calls = 0;
 
        if (!sleep_state_supported(state))
                return -EPERM;
 
        pm_prepare_console();
 
-       error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
-       if (error)
+       error = __pm_notifier_call_chain(PM_SUSPEND_PREPARE, -1, &nr_calls);
+       if (error) {
+               nr_calls--;
                goto Finish;
+       }
 
        trace_suspend_resume(TPS("freeze_processes"), 0, true);
        error = suspend_freeze_processes();
@@ -286,7 +288,7 @@ static int suspend_prepare(suspend_state_t state)
        suspend_stats.failed_freeze++;
        dpm_save_failed_step(SUSPEND_FREEZE);
  Finish:
-       pm_notifier_call_chain(PM_POST_SUSPEND);
+       __pm_notifier_call_chain(PM_POST_SUSPEND, nr_calls, NULL);
        pm_restore_console();
        return error;
 }

diff --git a/kernel/power/user.c b/kernel/power/user.c
index 526e8911460a0b550011b2aae89c1fe9ad11a2cf..35310b627388864b3125bce827e96d1a072c15b3 100644 (file)
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -47,7 +47,7 @@ atomic_t snapshot_device_available = ATOMIC_INIT(1);
 static int snapshot_open(struct inode *inode, struct file *filp)
 {
        struct snapshot_data *data;
-       int error;
+       int error, nr_calls = 0;
 
        if (!hibernation_available())
                return -EPERM;
@@ -74,9 +74,9 @@ static int snapshot_open(struct inode *inode, struct file *filp)
                        swap_type_of(swsusp_resume_device, 0, NULL) : -1;
                data->mode = O_RDONLY;
                data->free_bitmaps = false;
-               error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
+               error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
                if (error)
-                       pm_notifier_call_chain(PM_POST_HIBERNATION);
+                       __pm_notifier_call_chain(PM_POST_HIBERNATION, --nr_calls, NULL);
        } else {
                /*
                 * Resuming.  We may need to wait for the image device to
@@ -86,13 +86,15 @@ static int snapshot_open(struct inode *inode, struct file *filp)
 
                data->swap = -1;
                data->mode = O_WRONLY;
-               error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
+               error = __pm_notifier_call_chain(PM_RESTORE_PREPARE, -1, &nr_calls);
                if (!error) {
                        error = create_basic_memory_bitmaps();
                        data->free_bitmaps = !error;
-               }
+               } else
+                       nr_calls--;
+
                if (error)
-                       pm_notifier_call_chain(PM_POST_RESTORE);
+                       __pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
        }
        if (error)
                atomic_inc(&snapshot_device_available);