Suspend-related patches for 2.6.27

ACPI PM: Add possibility to change suspend sequence

There are some systems out there that don't work correctly with
our current suspend/hibernation code ordering.  Provide a workaround
for these systems allowing them to pass 'acpi_sleep=old_ordering' in
the kernel command line so that it will use the pre-ACPI 2.0 ("old")
suspend code ordering.

Unfortunately, this requires us to add a platform hook to the
resuming of devices for recovering the platform in case one of the
device drivers' .suspend() routines returns error code.  Namely,
ACPI 1.0 specifies that _PTS should be called before suspending
devices, but _WAK still should be called before resuming them in
order to undo the changes made by _PTS.  However, if there is an
error during suspending devices, they are automatically resumed
without returning control to the PM core, so the _WAK has to be
called from within device_resume() in that cases.

The patch also reorders and refactors the ACPI suspend/hibernation
code to avoid duplication as far as reasonably possible.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

2 files changed, 29 insertions, 9 deletions

diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index d416be0efa8a..f011e0870b52 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -180,6 +180,17 @@ static void platform_restore_cleanup(int platform_mode)
 }
 
 /**
+ *      platform_recover - recover the platform from a failure to suspend
+ *      devices.
+ */
+
+static void platform_recover(int platform_mode)
+{
+        if (platform_mode && hibernation_ops && hibernation_ops->recover)
+                hibernation_ops->recover();
+}
+
+/**
  *      create_image - freeze devices that need to be frozen with interrupts
  *      off, create the hibernation image and thaw those devices.  Control
  *      reappears in this routine after a restore.
@@ -258,10 +269,10 @@ int hibernation_snapshot(int platform_mode)
         suspend_console();
         error = device_suspend(PMSG_FREEZE);
         if (error)
-                goto Resume_console;
+                goto Recover_platform;
 
         if (hibernation_test(TEST_DEVICES))
-                goto Resume_devices;
+                goto Recover_platform;
 
         error = platform_pre_snapshot(platform_mode);
         if (error || hibernation_test(TEST_PLATFORM))
@@ -285,11 +296,14 @@ int hibernation_snapshot(int platform_mode)
  Resume_devices:
         device_resume(in_suspend ?
                 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
- Resume_console:
         resume_console();
  Close:
         platform_end(platform_mode);
         return error;
+
+ Recover_platform:
+        platform_recover(platform_mode);
+        goto Resume_devices;
 }
 
 /**
@@ -398,8 +412,11 @@ int hibernation_platform_enter(void)
 
         suspend_console();
         error = device_suspend(PMSG_HIBERNATE);
-        if (error)
-                goto Resume_console;
+        if (error) {
+                if (hibernation_ops->recover)
+                        hibernation_ops->recover();
+                goto Resume_devices;
+        }
 
         error = hibernation_ops->prepare();
         if (error)
@@ -428,7 +445,6 @@ int hibernation_platform_enter(void)
         hibernation_ops->finish();
  Resume_devices:
         device_resume(PMSG_RESTORE);
- Resume_console:
         resume_console();
  Close:
         hibernation_ops->end();
diff --git a/kernel/power/main.c b/kernel/power/main.c
index d023b6b584e5..3398f4651aa1 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -269,11 +269,11 @@ int suspend_devices_and_enter(suspend_state_t state)
         error = device_suspend(PMSG_SUSPEND);
         if (error) {
                 printk(KERN_ERR "PM: Some devices failed to suspend\n");
-                goto Resume_console;
+                goto Recover_platform;
         }
 
         if (suspend_test(TEST_DEVICES))
-                goto Resume_devices;
+                goto Recover_platform;
 
         if (suspend_ops->prepare) {
                 error = suspend_ops->prepare();
@@ -294,12 +294,16 @@ int suspend_devices_and_enter(suspend_state_t state)
                 suspend_ops->finish();
  Resume_devices:
         device_resume(PMSG_RESUME);
- Resume_console:
         resume_console();
  Close:
         if (suspend_ops->end)
                 suspend_ops->end();
         return error;
+
+ Recover_platform:
+        if (suspend_ops->recover)
+                suspend_ops->recover();
+        goto Resume_devices;
 }
 
 /**