Re: [PATCH 2/3] PM / Sleep: Make enter_state() in kernel/power/suspend.c static

From: Rafael J. Wysocki
Date: Sun Feb 12 2012 - 16:21:07 EST


On Sunday, February 12, 2012, Srivatsa S. Bhat wrote:
> On 02/12/2012 04:34 AM, Rafael J. Wysocki wrote:
>
> > From: Rafael J. Wysocki <rjw@xxxxxxx>
> >
> > The enter_state() function in kernel/power/suspend.c should be
> > static and state_store() in kernel/power/suspend.c should call
> > pm_suspend() instead of it, so make that happen (which also reduces
> > code duplication related to suspend statistics).
> >
> > Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
> > ---
> > kernel/power/main.c | 6 +-----
> > kernel/power/power.h | 2 --
> > kernel/power/suspend.c | 2 +-
> > 3 files changed, 2 insertions(+), 8 deletions(-)
> >
> > Index: linux/kernel/power/main.c
> > ===================================================================
> > --- linux.orig/kernel/power/main.c
> > +++ linux/kernel/power/main.c
> > @@ -292,11 +292,7 @@ static ssize_t state_store(struct kobjec
> > #ifdef CONFIG_SUSPEND
> > for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) {
> > if (*s && len == strlen(*s) && !strncmp(buf, *s, len))
> > - break;
> > - }
> > - if (state < PM_SUSPEND_MAX && *s) {
> > - error = enter_state(state);
> > - suspend_stats_update(error);
> > + error = pm_suspend(state);
>
>
> This code will not stop after calling pm_suspend(). It will try more iterations
> in the for loop right?

Well, only one string in pm_states[] can be matched at a time, but I agree that
it doesn't make sense to continue the loop after we've found a match.

> We can probably keep the 'for' loop as it is, and just replace the 'if' block
> following the 'for' loop by: error = pm_suspend(state);

I think the patch below is correct.

Thanks,
Rafael

---
From: Rafael J. Wysocki <rjw@xxxxxxx>
Subject: PM / Sleep: Make enter_state() in kernel/power/suspend.c static

The enter_state() function in kernel/power/suspend.c should be
static and state_store() in kernel/power/suspend.c should call
pm_suspend() instead of it, so make that happen (which also reduces
code duplication related to suspend statistics).

Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
---
kernel/power/main.c | 8 +++-----
kernel/power/power.h | 2 --
kernel/power/suspend.c | 2 +-
3 files changed, 4 insertions(+), 8 deletions(-)

Index: linux/kernel/power/main.c
===================================================================
--- linux.orig/kernel/power/main.c
+++ linux/kernel/power/main.c
@@ -291,12 +291,10 @@ static ssize_t state_store(struct kobjec

#ifdef CONFIG_SUSPEND
for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) {
- if (*s && len == strlen(*s) && !strncmp(buf, *s, len))
+ if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) {
+ error = pm_suspend(state);
break;
- }
- if (state < PM_SUSPEND_MAX && *s) {
- error = enter_state(state);
- suspend_stats_update(error);
+ }
}
#endif

Index: linux/kernel/power/power.h
===================================================================
--- linux.orig/kernel/power/power.h
+++ linux/kernel/power/power.h
@@ -177,13 +177,11 @@ extern const char *const pm_states[];

extern bool valid_state(suspend_state_t state);
extern int suspend_devices_and_enter(suspend_state_t state);
-extern int enter_state(suspend_state_t state);
#else /* !CONFIG_SUSPEND */
static inline int suspend_devices_and_enter(suspend_state_t state)
{
return -ENOSYS;
}
-static inline int enter_state(suspend_state_t state) { return -ENOSYS; }
static inline bool valid_state(suspend_state_t state) { return false; }
#endif /* !CONFIG_SUSPEND */

Index: linux/kernel/power/suspend.c
===================================================================
--- linux.orig/kernel/power/suspend.c
+++ linux/kernel/power/suspend.c
@@ -272,7 +272,7 @@ static void suspend_finish(void)
* Fail if that's not the case. Otherwise, prepare for system suspend, make the
* system enter the given sleep state and clean up after wakeup.
*/
-int enter_state(suspend_state_t state)
+static int enter_state(suspend_state_t state)
{
int error;

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