From 2391dae3e36c19fe668c71eac2eb8344dbaaf46d Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sun, 1 Jul 2007 12:07:33 -0700 Subject: [PATCH] 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 Acked-by: David Brownell Cc: Pavel Machek Cc: Johannes Berg Cc: Len Brown Cc: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/arm/mach-at91/pm.c | 4 +-- include/linux/pm.h | 62 +++++++++++++++++++++++++++++++---------- kernel/power/main.c | 6 +++- 3 files changed, 54 insertions(+), 18 deletions(-) diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c index 47ff676aca..ddf9184d56 100644 --- a/arch/arm/mach-at91/pm.c +++ b/arch/arm/mach-at91/pm.c @@ -53,7 +53,7 @@ static suspend_state_t target_state; /* * Called after processes are frozen, but before we shutdown devices. */ -static int at91_pm_prepare(suspend_state_t state) +static int at91_pm_set_target(suspend_state_t state) { target_state = state; return 0; @@ -201,7 +201,7 @@ error: static struct pm_ops at91_pm_ops ={ .valid = at91_pm_valid_state, - .prepare = at91_pm_prepare, + .set_target = at91_pm_set_target, .enter = at91_pm_enter, }; diff --git a/include/linux/pm.h b/include/linux/pm.h index 87545e0f0b..b2c4fde4e9 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 */ diff --git a/kernel/power/main.c b/kernel/power/main.c index 8812985f30..fc45ed2262 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -15,7 +15,6 @@ #include #include #include -#include #include #include #include @@ -97,6 +96,11 @@ static int suspend_prepare(suspend_state_t state) } } + if (pm_ops->set_target) { + error = pm_ops->set_target(state); + if (error) + goto Thaw; + } suspend_console(); error = device_suspend(PMSG_SUSPEND); if (error) { -- 2.39.5