diff options
Diffstat (limited to 'kernel/power/main.c')
-rw-r--r-- | kernel/power/main.c | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/kernel/power/main.c b/kernel/power/main.c index 22bdc93cc03..d253f3ae2fa 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -24,7 +24,7 @@ DECLARE_MUTEX(pm_sem); -struct pm_ops * pm_ops = NULL; +struct pm_ops *pm_ops; suspend_disk_method_t pm_disk_mode = PM_DISK_SHUTDOWN; /** @@ -151,6 +151,18 @@ static char *pm_states[PM_SUSPEND_MAX] = { #endif }; +static inline int valid_state(suspend_state_t state) +{ + /* Suspend-to-disk does not really need low-level support. + * It can work with reboot if needed. */ + if (state == PM_SUSPEND_DISK) + return 1; + + if (pm_ops && pm_ops->valid && !pm_ops->valid(state)) + return 0; + return 1; +} + /** * enter_state - Do common work of entering low-power state. @@ -167,6 +179,8 @@ static int enter_state(suspend_state_t state) { int error; + if (!valid_state(state)) + return -ENODEV; if (down_trylock(&pm_sem)) return -EBUSY; @@ -236,8 +250,8 @@ static ssize_t state_show(struct subsystem * subsys, char * buf) char * s = buf; for (i = 0; i < PM_SUSPEND_MAX; i++) { - if (pm_states[i]) - s += sprintf(s,"%s ",pm_states[i]); + if (pm_states[i] && valid_state(i)) + s += sprintf(s,"%s ", pm_states[i]); } s += sprintf(s,"\n"); return (s - buf); |