[RFC PATCH 2/3] PM: Add prepare_late/finish_early suspend_ops callbacks

From: Lv Zheng
Date: Tue Jun 28 2016 - 04:04:53 EST


This patch adds prepare_late/finish_early callbacks for suspend_ops.

Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx>
---
include/linux/suspend.h | 34 +++++++++++++++++++++++++++-------
kernel/power/suspend.c | 10 ++++++++--
2 files changed, 35 insertions(+), 9 deletions(-)

diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index b5261e3..21e32b8 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -115,14 +115,24 @@ static inline void dpm_save_failed_step(enum suspend_stat_step step)
* This callback is optional. However, if it is implemented, the argument
* passed to @enter() is redundant and should be ignored.
*
- * @prepare: Prepare the platform for entering the system sleep state indicated
- * by @begin().
+ * @prepare: Early preparing the platform for entering the system sleep state
+ * indicated by @begin().
* @prepare() is called right after devices have been suspended (ie. the
* appropriate .suspend() method has been executed for each device) and
* before device drivers' late suspend callbacks are executed. It returns
* 0 on success or a negative error code otherwise, in which case the
- * system cannot enter the desired sleep state (@prepare_noirq(), @enter(),
- * and @finish_noirq() will not be called in that case).
+ * system cannot enter the desired sleep state (@prepare_late,
+ * @prepare_noirq(), @enter(), and @finish_noirq() will not be called in
+ * that case).
+ *
+ * @prepare_late: Late preparing the platform for entering the system sleep
+ * state indicated by @begin().
+ * @prepare_late() is called right after device drivers' late suspend
+ * callbacks have been executed and before device drivers' noirq suspend
+ * callbacks are executed. It returns 0 on success or a negative error
+ * code otherwise, in which case the system cannot enter the desired sleep
+ * state (@prepare_noirq(), @enter(), and @finish_noirq() will not be
+ * called in that case).
*
* @prepare_noirq: Finish preparing the platform for entering the system sleep
* state indicated by @begin().
@@ -145,13 +155,21 @@ static inline void dpm_save_failed_step(enum suspend_stat_step step)
* that implement @prepare_noirq(). If implemented, it is always called
* after @prepare_noirq and @enter(), even if one of them fails.
*
- * @finish: Finish wake-up of the platform.
+ * @finish_early: Early finishing wake-up of the platform.
+ * @finish_early is called right prior to calling device drivers' resume
+ * early callbacks.
+ * This callback is optional, but should be implemented by the platforms
+ * that implement @prepare_late(). If implemented, it is always called
+ * after @enter() and @finish_noirq(), even if any of them fails. It is
+ * executed after a failing @prepare_late.
+ *
+ * @finish: Late finishing wake-up of the platform.
* @finish is called right prior to calling device drivers' regular suspend
* callbacks.
* This callback is optional, but should be implemented by the platforms
* that implement @prepare(). If implemented, it is always called after
- * @enter() and @finish_noirq(), even if any of them fails. It is executed
- * after a failing @prepare.
+ * @enter(), @finish_noirq() and @finish_early, even if any of them fails.
+ * It is executed after a failing @prepare.
*
* @suspend_again: Returns whether the system should suspend again (true) or
* not (false). If the platform wants to poll sensors or execute some
@@ -177,9 +195,11 @@ struct platform_suspend_ops {
int (*valid)(suspend_state_t state);
int (*begin)(suspend_state_t state);
int (*prepare)(void);
+ int (*prepare_late)(void);
int (*prepare_noirq)(void);
int (*enter)(suspend_state_t state);
void (*finish_noirq)(void);
+ void (*finish_early)(void);
void (*finish)(void);
bool (*suspend_again)(void);
void (*end)(void);
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index f0a5561..3a36107 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -179,8 +179,12 @@ static int platform_suspend_prepare(suspend_state_t state)

static int platform_suspend_prepare_late(suspend_state_t state)
{
- return state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->prepare ?
- freeze_ops->prepare() : 0;
+ if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->prepare)
+ return freeze_ops->prepare();
+ else if (suspend_ops->prepare_late)
+ return suspend_ops->prepare_late();
+ else
+ return 0;
}

static int platform_suspend_prepare_noirq(suspend_state_t state)
@@ -199,6 +203,8 @@ static void platform_resume_early(suspend_state_t state)
{
if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->restore)
freeze_ops->restore();
+ else if (suspend_ops->finish_early)
+ suspend_ops->finish_early();
}

static void platform_resume_finish(suspend_state_t state)
--
1.7.10