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PM: introduce set_target method in pm_ops 

Commit 52ade9b3b9 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>
This commit is contained in:
Rafael J. Wysocki 2007-07-01 12:07:33 -07:00 committed by Linus Torvalds
parent cbcdd772ff
commit 2391dae3e3
3 changed files with 54 additions and 18 deletions
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4
arch/arm/mach-at91/pm.c
View File

@ -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,
};

62
include/linux/pm.h
View File

@ -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
*/

6
kernel/power/main.c
View File

@ -15,7 +15,6 @@
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/pm.h>
#include <linux/console.h>
#include <linux/cpu.h>
#include <linux/resume-trace.h>
@ -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) {