History

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
  1. arch/arm/mach-at91/pm.c +2 −2
  2. include/linux/pm.h +47 −15
  3. 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 * Called after processes are frozen, but before we shutdown devices.54 * Called after processes are frozen, but before we shutdown devices.
55 */55 */
56static int at91_pm_prepare(suspend_state_t state)56static int at91_pm_set_target(suspend_state_t state)
57{57{
58 target_state = state;58 target_state = state;
59 return 0;59 return 0;
@@ -201,7 +201,7 @@ error: · 141 unmodified lines
201 201
202static struct pm_ops at91_pm_ops ={202static struct pm_ops at91_pm_ops ={
203 .valid = at91_pm_valid_state,203 .valid = at91_pm_valid_state,
204 .prepare = at91_pm_prepare,204 .set_target = at91_pm_set_target,
205 .enter = at91_pm_enter,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#define PM_SUSPEND_MAX ((__force suspend_state_t) 4)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.113 * struct pm_ops - Callbacks for managing platform dependent system sleep
114 * @valid: Callback to determine whether the given state can be entered.114 * states.
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.
119 *115 *
120 * @prepare: Prepare the platform for the given suspend state. Can return a116 * @valid: Callback to determine if given system sleep state is supported by
121 * negative error code if necessary.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 a124 * @set_target: Tell the platform which system sleep state is going to be
124 * negative error code if necessary.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 devices135 * @prepare: Prepare the platform for entering the system sleep state indicated
127 * are resumed. The return value is ignored.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 */
129struct pm_ops {159struct pm_ops {
130 int (*valid)(suspend_state_t state);160 int (*valid)(suspend_state_t state);
161 int (*set_target)(suspend_state_t state);
131 int (*prepare)(suspend_state_t state);162 int (*prepare)(suspend_state_t state);
132 int (*enter)(suspend_state_t state);163 int (*enter)(suspend_state_t state);
133 int (*finish)(suspend_state_t state);164 int (*finish)(suspend_state_t state);
134};165};
135 166
167extern struct pm_ops *pm_ops;
168
136/**169/**
137 * pm_set_ops - set platform dependent power management ops170 * pm_set_ops - set platform dependent power management ops
138 * @pm_ops: The new power management operations to set.171 * @pm_ops: The new power management operations to set.
139 */172 */
140extern void pm_set_ops(struct pm_ops *pm_ops);173extern void pm_set_ops(struct pm_ops *pm_ops);
141extern struct pm_ops *pm_ops;
142extern int pm_suspend(suspend_state_t state);
143
144extern int pm_valid_only_mem(suspend_state_t state);174extern 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 */
162extern void arch_suspend_enable_irqs(void);192extern void arch_suspend_enable_irqs(void);
163 193
194extern int pm_suspend(suspend_state_t state);
195
164/*196/*
165 * Device power management197 * Device power management
166 */198 */
kernel/power/main.c+5−1
@@ -15,7 +15,6 @@ · 14 unmodified lines
15#include <linux/delay.h>15#include <linux/delay.h>
16#include <linux/errno.h>16#include <linux/errno.h>
17#include <linux/init.h>17#include <linux/init.h>
18#include <linux/pm.h>
19#include <linux/console.h>18#include <linux/console.h>
20#include <linux/cpu.h>19#include <linux/cpu.h>
21#include <linux/resume-trace.h>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 suspend_console();104 suspend_console();
101 error = device_suspend(PMSG_SUSPEND);105 error = device_suspend(PMSG_SUSPEND);
102 if (error) {106 if (error) {