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, 16 insertions, 1 deletions

diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 41f7ce7edd7a..33adcf91ef41 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -234,6 +234,9 @@ int acpi_check_region(resource_size_t start, resource_size_t n,
 int acpi_check_mem_region(resource_size_t start, resource_size_t n,
                       const char *name);
 
+#ifdef CONFIG_PM_SLEEP
+void __init acpi_old_suspend_ordering(void);
+#endif /* CONFIG_PM_SLEEP */
 #else   /* CONFIG_ACPI */
 
 static inline int early_acpi_boot_init(void)
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index a6977423baf7..e8e69159af71 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -86,6 +86,11 @@ typedef int __bitwise suspend_state_t;
  *      that implement @begin(), but platforms implementing @begin() should
  *      also provide a @end() which cleans up transitions aborted before
  *      @enter().
+ *
+ * @recover: Recover the platform from a suspend failure.
+ *      Called by the PM core if the suspending of devices fails.
+ *      This callback is optional and should only be implemented by platforms
+ *      which require special recovery actions in that situation.
  */
 struct platform_suspend_ops {
         int (*valid)(suspend_state_t state);
@@ -94,6 +99,7 @@ struct platform_suspend_ops {
         int (*enter)(suspend_state_t state);
         void (*finish)(void);
         void (*end)(void);
+        void (*recover)(void);
 };
 
 #ifdef CONFIG_SUSPEND
@@ -149,7 +155,7 @@ extern void mark_free_pages(struct zone *zone);
  * The methods in this structure allow a platform to carry out special
  * operations required by it during a hibernation transition.
  *
- * All the methods below must be implemented.
+ * All the methods below, except for @recover(), must be implemented.
  *
  * @begin: Tell the platform driver that we're starting hibernation.
  *      Called right after shrinking memory and before freezing devices.
@@ -189,6 +195,11 @@ extern void mark_free_pages(struct zone *zone);
  * @restore_cleanup: Clean up after a failing image restoration.
  *      Called right after the nonboot CPUs have been enabled and before
  *      thawing devices (runs with IRQs on).
+ *
+ * @recover: Recover the platform from a failure to suspend devices.
+ *      Called by the PM core if the suspending of devices during hibernation
+ *      fails.  This callback is optional and should only be implemented by
+ *      platforms which require special recovery actions in that situation.
  */
 struct platform_hibernation_ops {
         int (*begin)(void);
@@ -200,6 +211,7 @@ struct platform_hibernation_ops {
         void (*leave)(void);
         int (*pre_restore)(void);
         void (*restore_cleanup)(void);
+        void (*recover)(void);
 };
 
 #ifdef CONFIG_HIBERNATION