This patch changes /sys/power/state to not advertise any valid states
(except for disk if SOFTWARE_SUSPEND is enabled) when no pm_ops have been
set so userspace can easily discover what states should be available.
Also, because the pm ops in powermac are obviously not using them as
intended, I added documentation for it in kernel-doc format.
Reordering the fields in struct pm_ops not only makes the output of
kernel-doc make more sense but also removes a hole from the structure on
64-bit platforms.
Signed-off-by: Johannes Berg <johannes at sipsolutions.net>
Cc: linux-pm at lists.osdl.org
Cc: Rafael J. Wysocki <rjw at sisk.pl>
Cc: Pavel Macheck <pavel at ucw.cz>
---
include/linux/pm.h | 37 +++++++++++++++++++++++++++++++++++--
kernel/power/main.c | 5 ++++-
2 files changed, 39 insertions(+), 3 deletions(-)
--- linux-2.6.orig/kernel/power/main.c 2007-02-09 15:23:30.413842184 +0100
+++ linux-2.6/kernel/power/main.c 2007-02-13 18:32:12.876706009 +0100
@@ -161,7 +161,10 @@ static inline int valid_state(suspend_st
if (state == PM_SUSPEND_DISK)
return 1;
- if (pm_ops && pm_ops->valid && !pm_ops->valid(state))
+ /* all other states need lowlevel support and need to be
+ * valid to the lowlevel implementation, no valid callback
+ * implies that all are valid. */
+ if (!pm_ops || (pm_ops->valid && !pm_ops->valid(state)))
return 0;
return 1;
}
--- linux-2.6.orig/include/linux/pm.h 2007-02-09 15:23:30.503842184 +0100
+++ linux-2.6/include/linux/pm.h 2007-02-13 19:02:46.157177125 +0100
@@ -120,15 +120,48 @@ typedef int __bitwise suspend_disk_metho
#define PM_DISK_TESTPROC ((__force suspend_disk_method_t) 6)
#define PM_DISK_MAX ((__force suspend_disk_method_t) 7)
+/**
+ * struct pm_ops - Callbacks for managing platform dependent suspend states.
+ * @valid: Callback to determine whether the given state can be entered.
+ * If %CONFIG_SOFTWARE_SUSPEND is set then %PM_SUSPEND_DISK is
+ * always valid and never passed to this call.
+ * If not assigned, all suspend states are advertised as valid
+ * in /sys/power/state (but can still be rejected by prepare or enter.)
+ *
+ * @prepare: Prepare the platform for the given suspend state. Can return a
+ * negative error code if necessary.
+ *
+ * @enter: Enter the given suspend state, must be assigned. Can return a
+ * negative error code if necessary.
+ *
+ * @finish: Called when the system has left the given state and all devices
+ * are resumed. The return value is ignored.
+ *
+ * @pm_disk_mode: Set to the disk method that the user should be able to
+ * configure for suspend-to-disk. Since %PM_DISK_SHUTDOWN,
+ * %PM_DISK_REBOOT, %PM_DISK_TEST and %PM_DISK_TESTPROC
+ * are always allowed, currently only %PM_DISK_PLATFORM
+ * makes sense. If the user then choses %PM_DISK_PLATFORM,
+ * the @prepare call will be called before suspending to disk
+ * (if present), the @enter call should be present and will
+ * be called after all state has been saved and the machine
+ * is ready to be shut down/suspended/..., and the @finish
+ * callback is called after state has been restored. All
+ * these calls are called with %PM_SUSPEND_DISK as the state.
+ */
struct pm_ops {
- suspend_disk_method_t pm_disk_mode;
int (*valid)(suspend_state_t state);
int (*prepare)(suspend_state_t state);
int (*enter)(suspend_state_t state);
int (*finish)(suspend_state_t state);
+ suspend_disk_method_t pm_disk_mode;
};
-extern void pm_set_ops(struct pm_ops *);
+/**
+ * pm_set_ops - set platform dependent power management ops
+ * @pm_ops: The new power management operations to set.
+ */
+extern void pm_set_ops(struct pm_ops *pm_ops);
extern struct pm_ops *pm_ops;
extern int pm_suspend(suspend_state_t state);
