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authorRafael J. Wysocki <rjw@sisk.pl>2007-07-01 19:07:33 (GMT)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-01 19:29:44 (GMT)
commit2391dae3e36c19fe668c71eac2eb8344dbaaf46d (patch)
treeae8c1fa53fe67e3ccbb8c5097f6b5bda27b26959
parentcbcdd772ff43de58cc0d9de76ae9d05e2dd98bc0 (diff)
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>
-rw-r--r--arch/arm/mach-at91/pm.c4
-rw-r--r--include/linux/pm.h62
-rw-r--r--kernel/power/main.c6
3 files changed, 54 insertions, 18 deletions
diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
index 47ff676..ddf9184 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 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
*/
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 8812985..fc45ed2 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -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) {

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