[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>

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 7406fe6966f908cb547fba3de5fcf5d566f831ea..3d4206ada5c9d970c0806348a75424f30f7adbac 100644 (file)
--- 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 88fc5d7ac737402c18db0306049b5873effeed55..406b20adb27ad820a455b93a836ab636cbf65436 100644 (file)
--- 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 */