[PATCH] swsusp: Change code ordering in disk.c

Change the ordering of code in kernel/power/disk.c so that device_suspend() is
called before disable_nonboot_cpus() and platform_finish() is called after
enable_nonboot_cpus() and before device_resume(), as indicated by the recent
discussion on Linux-PM (cf.
http://lists.osdl.org/pipermail/linux-pm/2006-November/004164.html).

The changes here only affect the built-in swsusp.

[alexey.y.starikovskiy@linux.intel.com: fix LED blinking during image load]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Greg KH <greg@kroah.com>
Cc: Nigel Cunningham <nigel@suspend2.net>
Cc: Patrick Mochel <mochel@digitalimplant.org>
Cc: Alexey Starikovskiy <alexey.y.starikovskiy@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 60 insertions, 57 deletions

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 7406fe6966f9..3d4206ada5c9 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -309,6 +309,8 @@ void enable_nonboot_cpus(void)
         mutex_lock(&cpu_add_remove_lock);
         cpu_hotplug_disabled = 0;
         mutex_unlock(&cpu_add_remove_lock);
+        if (cpus_empty(frozen_cpus))
+                return;
 
         printk("Enabling non-boot CPUs ...\n");
         for_each_cpu_mask(cpu, frozen_cpus) {
diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index 88fc5d7ac737..406b20adb27a 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -87,52 +87,24 @@ static inline void platform_finish(void)
         }
 }
 
+static void unprepare_processes(void)
+{
+        thaw_processes();
+        pm_restore_console();
+}
+
 static int prepare_processes(void)
 {
         int error = 0;
 
         pm_prepare_console();
-
-        error = disable_nonboot_cpus();
-        if (error)
-                goto enable_cpus;
-
         if (freeze_processes()) {
                 error = -EBUSY;
-                goto thaw;
+                unprepare_processes();
         }
-
-        if (pm_disk_mode == PM_DISK_TESTPROC) {
-                printk("swsusp debug: Waiting for 5 seconds.\n");
-                mdelay(5000);
-                goto thaw;
-        }
-
-        error = platform_prepare();
-        if (error)
-                goto thaw;
-
-        /* Free memory before shutting down devices. */
-        if (!(error = swsusp_shrink_memory()))
-                return 0;
-
-        platform_finish();
- thaw:
-        thaw_processes();
- enable_cpus:
-        enable_nonboot_cpus();
-        pm_restore_console();
         return error;
 }
 
-static void unprepare_processes(void)
-{
-        platform_finish();
-        thaw_processes();
-        enable_nonboot_cpus();
-        pm_restore_console();
-}
-
 /**
  *      pm_suspend_disk - The granpappy of hibernation power management.
  *
@@ -150,29 +122,45 @@ int pm_suspend_disk(void)
         if (error)
                 return error;
 
-        if (pm_disk_mode == PM_DISK_TESTPROC)
-                return 0;
+        if (pm_disk_mode == PM_DISK_TESTPROC) {
+                printk("swsusp debug: Waiting for 5 seconds.\n");
+                mdelay(5000);
+                goto Thaw;
+        }
+        /* Free memory before shutting down devices. */
+        error = swsusp_shrink_memory();
+        if (error)
+                goto Thaw;
+
+        error = platform_prepare();
+        if (error)
+                goto Thaw;
 
         suspend_console();
         error = device_suspend(PMSG_FREEZE);
         if (error) {
-                resume_console();
-                printk("Some devices failed to suspend\n");
-                goto Thaw;
+                printk(KERN_ERR "PM: Some devices failed to suspend\n");
+                goto Resume_devices;
         }
+        error = disable_nonboot_cpus();
+        if (error)
+                goto Enable_cpus;
 
         if (pm_disk_mode == PM_DISK_TEST) {
                 printk("swsusp debug: Waiting for 5 seconds.\n");
                 mdelay(5000);
-                goto Done;
+                goto Enable_cpus;
         }
 
         pr_debug("PM: snapshotting memory.\n");
         in_suspend = 1;
-        if ((error = swsusp_suspend()))
-                goto Done;
+        error = swsusp_suspend();
+        if (error)
+                goto Enable_cpus;
 
         if (in_suspend) {
+                enable_nonboot_cpus();
+                platform_finish();
                 device_resume();
                 resume_console();
                 pr_debug("PM: writing image.\n");
@@ -188,7 +176,10 @@ int pm_suspend_disk(void)
         }
 
         swsusp_free();
- Done:
+ Enable_cpus:
+        enable_nonboot_cpus();
+ Resume_devices:
+        platform_finish();
         device_resume();
         resume_console();
  Thaw:
@@ -237,19 +228,28 @@ static int software_resume(void)
 
         pr_debug("PM: Checking swsusp image.\n");
 
-        if ((error = swsusp_check()))
+        error = swsusp_check();
+        if (error)
                 goto Done;
 
         pr_debug("PM: Preparing processes for restore.\n");
 
-        if ((error = prepare_processes())) {
+        error = prepare_processes();
+        if (error) {
                 swsusp_close();
                 goto Done;
         }
 
+        error = platform_prepare();
+        if (error) {
+                swsusp_free();
+                goto Thaw;
+        }
+
         pr_debug("PM: Reading swsusp image.\n");
 
-        if ((error = swsusp_read())) {
+        error = swsusp_read();
+        if (error) {
                 swsusp_free();
                 goto Thaw;
         }
@@ -257,21 +257,22 @@ static int software_resume(void)
         pr_debug("PM: Preparing devices for restore.\n");
 
         suspend_console();
-        if ((error = device_suspend(PMSG_PRETHAW))) {
-                resume_console();
-                printk("Some devices failed to suspend\n");
-                swsusp_free();
-                goto Thaw;
-        }
+        error = device_suspend(PMSG_PRETHAW);
+        if (error)
+                goto Free;
 
-        mb();
+        error = disable_nonboot_cpus();
+        if (!error)
+                swsusp_resume();
 
-        pr_debug("PM: Restoring saved image.\n");
-        swsusp_resume();
-        pr_debug("PM: Restore failed, recovering.n");
+        enable_nonboot_cpus();
+ Free:
+        swsusp_free();
+        platform_finish();
         device_resume();
         resume_console();
  Thaw:
+        printk(KERN_ERR "PM: Restore failed, recovering.\n");
         unprepare_processes();
  Done:
         /* For success case, the suspend path will release the lock */