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author | Rafael J. Wysocki <rjw@sisk.pl> | 2007-07-01 19:07:33 (GMT) |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-01 19:29:44 (GMT) |
commit | 2391dae3e36c19fe668c71eac2eb8344dbaaf46d (patch) | |
tree | ae8c1fa53fe67e3ccbb8c5097f6b5bda27b26959 /include | |
parent | cbcdd772ff43de58cc0d9de76ae9d05e2dd98bc0 (diff) | |
download | linux-2391dae3e36c19fe668c71eac2eb8344dbaaf46d.tar.xz |
PM: introduce set_target method in pm_ops
Commit 52ade9b3b97fd3bea42842a056fe0786c28d0555 changed the suspend code
ordering to execute pm_ops->prepare() after the device model per-device
.suspend() calls in order to fix some ACPI-related issues. Unfortunately, it
broke the at91 platform which assumed that pm_ops->prepare() would be called
before suspending devices.
at91 used pm_ops->prepare() to get notified of the target system sleep state,
so that it could use this information while suspending devices. However, with
the current suspend code ordering pm_ops->prepare() is called too late for
this purpose. Thus, at91 needs an additional method in 'struct pm_ops' that
will be used for notifying the platform of the target system sleep state.
Moreover, in the future such a method will also be needed by ACPI.
This patch adds the .set_target() method to 'struct pm_ops' and makes the
suspend code call it, if implemented, before executing the device model
per-device .suspend() calls. It also modifies the at91 code to use
pm_ops->set_target() instead of pm_ops->prepare().
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/pm.h | 62 |
1 files changed, 47 insertions, 15 deletions
diff --git a/include/linux/pm.h b/include/linux/pm.h index 87545e0..b2c4fde 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -110,37 +110,67 @@ typedef int __bitwise suspend_state_t; #define PM_SUSPEND_MAX ((__force suspend_state_t) 4) /** - * struct pm_ops - Callbacks for managing platform dependent suspend states. - * @valid: Callback to determine whether the given state can be entered. - * Valid states are advertised in /sys/power/state but can still - * be rejected by prepare or enter if the conditions aren't right. - * There is a %pm_valid_only_mem function available that can be assigned - * to this if you only implement mem sleep. + * struct pm_ops - Callbacks for managing platform dependent system sleep + * states. * - * @prepare: Prepare the platform for the given suspend state. Can return a - * negative error code if necessary. + * @valid: Callback to determine if given system sleep state is supported by + * the platform. + * Valid (ie. supported) states are advertised in /sys/power/state. Note + * that it still may be impossible to enter given system sleep state if the + * conditions aren't right. + * There is the %pm_valid_only_mem function available that can be assigned + * to this if the platform only supports mem sleep. * - * @enter: Enter the given suspend state, must be assigned. Can return a - * negative error code if necessary. + * @set_target: Tell the platform which system sleep state is going to be + * entered. + * @set_target() is executed right prior to suspending devices. The + * information conveyed to the platform code by @set_target() should be + * disregarded by the platform as soon as @finish() is executed and if + * @prepare() fails. If @set_target() fails (ie. returns nonzero), + * @prepare(), @enter() and @finish() will not be called by the PM core. + * This callback is optional. However, if it is implemented, the argument + * passed to @prepare(), @enter() and @finish() is meaningless and should + * be ignored. * - * @finish: Called when the system has left the given state and all devices - * are resumed. The return value is ignored. + * @prepare: Prepare the platform for entering the system sleep state indicated + * by @set_target() or represented by the argument if @set_target() is not + * implemented. + * @prepare() is called right after devices have been suspended (ie. the + * appropriate .suspend() method has been executed for each device) and + * before the nonboot CPUs are disabled (it is executed with IRQs enabled). + * This callback is optional. It returns 0 on success or a negative + * error code otherwise, in which case the system cannot enter the desired + * sleep state (@enter() and @finish() will not be called in that case). + * + * @enter: Enter the system sleep state indicated by @set_target() or + * represented by the argument if @set_target() is not implemented. + * This callback is mandatory. It returns 0 on success or a negative + * error code otherwise, in which case the system cannot enter the desired + * sleep state. + * + * @finish: Called when the system has just left a sleep state, right after + * the nonboot CPUs have been enabled and before devices are resumed (it is + * executed with IRQs enabled). If @set_target() is not implemented, the + * argument represents the sleep state being left. + * This callback is optional, but should be implemented by the platforms + * that implement @prepare(). If implemented, it is always called after + * @enter() (even if @enter() fails). */ struct pm_ops { int (*valid)(suspend_state_t state); + int (*set_target)(suspend_state_t state); int (*prepare)(suspend_state_t state); int (*enter)(suspend_state_t state); int (*finish)(suspend_state_t state); }; +extern struct pm_ops *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); - extern int pm_valid_only_mem(suspend_state_t state); /** @@ -161,6 +191,8 @@ extern void arch_suspend_disable_irqs(void); */ extern void arch_suspend_enable_irqs(void); +extern int pm_suspend(suspend_state_t state); + /* * Device power management */ |