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().

Rafael J. Wysocki committed 19 years ago

Commit 2391dae1 parent cbcdd773 files · +54 −18Browse files

Unified · Split

3 files

arch/arm/mach-at91/pm.c +2 −2
include/linux/pm.h +47 −15
kernel/power/main.c +5 −1

arch/arm/mach-at91/pm.c+2−2

@@ -53,7 +53,7 @@ static suspend_state_t target_state; · 52 unmodified lines
53	53	/*
54	54	* Called after processes are frozen, but before we shutdown devices.
55	55	*/
56		−static int at91_pm_prepare(suspend_state_t state)
	56	+static int at91_pm_set_target(suspend_state_t state)
57	57	{
58	58	target_state = state;
59	59	return 0;
@@ -201,7 +201,7 @@ error: · 141 unmodified lines
201	201
202	202	static struct pm_ops at91_pm_ops ={
203	203	.valid = at91_pm_valid_state,
204		− .prepare = at91_pm_prepare,
	204	+ .set_target = at91_pm_set_target,
205	205	.enter = at91_pm_enter,
206	206	};
207	207

include/linux/pm.h+47−15

@@ -110,37 +110,67 @@ typedef int __bitwise suspend_state_t; · 109 unmodified lines
110	110	#define PM_SUSPEND_MAX ((__force suspend_state_t) 4)
111	111
112	112	/**
113		− * struct pm_ops - Callbacks for managing platform dependent suspend states.
114		− * @valid: Callback to determine whether the given state can be entered.
115		− * Valid states are advertised in /sys/power/state but can still
116		− * be rejected by prepare or enter if the conditions aren't right.
117		− * There is a %pm_valid_only_mem function available that can be assigned
118		− * to this if you only implement mem sleep.
	113	+ * struct pm_ops - Callbacks for managing platform dependent system sleep
	114	+ * states.
119	115	*
120		− * @prepare: Prepare the platform for the given suspend state. Can return a
121		− * negative error code if necessary.
	116	+ * @valid: Callback to determine if given system sleep state is supported by
	117	+ * the platform.
	118	+ * Valid (ie. supported) states are advertised in /sys/power/state. Note
	119	+ * that it still may be impossible to enter given system sleep state if the
	120	+ * conditions aren't right.
	121	+ * There is the %pm_valid_only_mem function available that can be assigned
	122	+ * to this if the platform only supports mem sleep.
122	123	*
123		− * @enter: Enter the given suspend state, must be assigned. Can return a
124		− * negative error code if necessary.
	124	+ * @set_target: Tell the platform which system sleep state is going to be
	125	+ * entered.
	126	+ * @set_target() is executed right prior to suspending devices. The
	127	+ * information conveyed to the platform code by @set_target() should be
	128	+ * disregarded by the platform as soon as @finish() is executed and if
	129	+ * @prepare() fails. If @set_target() fails (ie. returns nonzero),
	130	+ * @prepare(), @enter() and @finish() will not be called by the PM core.
	131	+ * This callback is optional. However, if it is implemented, the argument
	132	+ * passed to @prepare(), @enter() and @finish() is meaningless and should
	133	+ * be ignored.
125	134	*
126		− * @finish: Called when the system has left the given state and all devices
127		− * are resumed. The return value is ignored.
	135	+ * @prepare: Prepare the platform for entering the system sleep state indicated
	136	+ * by @set_target() or represented by the argument if @set_target() is not
	137	+ * implemented.
	138	+ * @prepare() is called right after devices have been suspended (ie. the
	139	+ * appropriate .suspend() method has been executed for each device) and
	140	+ * before the nonboot CPUs are disabled (it is executed with IRQs enabled).
	141	+ * This callback is optional. It returns 0 on success or a negative
	142	+ * error code otherwise, in which case the system cannot enter the desired
	143	+ * sleep state (@enter() and @finish() will not be called in that case).
	144	+ *
	145	+ * @enter: Enter the system sleep state indicated by @set_target() or
	146	+ * represented by the argument if @set_target() is not implemented.
	147	+ * This callback is mandatory. It returns 0 on success or a negative
	148	+ * error code otherwise, in which case the system cannot enter the desired
	149	+ * sleep state.
	150	+ *
	151	+ * @finish: Called when the system has just left a sleep state, right after
	152	+ * the nonboot CPUs have been enabled and before devices are resumed (it is
	153	+ * executed with IRQs enabled). If @set_target() is not implemented, the
	154	+ * argument represents the sleep state being left.
	155	+ * This callback is optional, but should be implemented by the platforms
	156	+ * that implement @prepare(). If implemented, it is always called after
	157	+ * @enter() (even if @enter() fails).
128	158	*/
129	159	struct pm_ops {
130	160	int (*valid)(suspend_state_t state);
	161	+ int (*set_target)(suspend_state_t state);
131	162	int (*prepare)(suspend_state_t state);
132	163	int (*enter)(suspend_state_t state);
133	164	int (*finish)(suspend_state_t state);
134	165	};
135	166
	167	+extern struct pm_ops *pm_ops;
	168	+
136	169	/**
137	170	* pm_set_ops - set platform dependent power management ops
138	171	* @pm_ops: The new power management operations to set.
139	172	*/
140	173	extern void pm_set_ops(struct pm_ops *pm_ops);
141		−extern struct pm_ops *pm_ops;
142		−extern int pm_suspend(suspend_state_t state);
143		−
144	174	extern int pm_valid_only_mem(suspend_state_t state);
145	175
146	176	/**
@@ -161,6 +191,8 @@ extern void arch_suspend_disable_irqs(void); · 14 unmodified lines
161	191	*/
162	192	extern void arch_suspend_enable_irqs(void);
163	193
	194	+extern int pm_suspend(suspend_state_t state);
	195	+
164	196	/*
165	197	* Device power management
166	198	*/

kernel/power/main.c+5−1

@@ -15,7 +15,6 @@ · 14 unmodified lines
15	15	#include <linux/delay.h>
16	16	#include <linux/errno.h>
17	17	#include <linux/init.h>
18		−#include <linux/pm.h>
19	18	#include <linux/console.h>
20	19	#include <linux/cpu.h>
21	20	#include <linux/resume-trace.h>
@@ -97,6 +96,11 @@ static int suspend_prepare(suspend_state_t state) · 75 unmodified lines
97	96	}
98	97	}
99	98
	99	+ if (pm_ops->set_target) {
	100	+ error = pm_ops->set_target(state);
	101	+ if (error)
	102	+ goto Thaw;
	103	+ }
100	104	suspend_console();
101	105	error = device_suspend(PMSG_SUSPEND);
102	106	if (error) {