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().
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| @@ -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 | */ |