dpm_suspend_start
dpm_suspend_start(PMSG_SUSPEND);
EXPORT_SYMBOL_GPL(dpm_suspend_start);
err = dpm_suspend_start(PMSG_FREEZE);
extern int dpm_suspend_start(pm_message_t state);
error = dpm_suspend_start(PMSG_FREEZE);
error = dpm_suspend_start(PMSG_QUIESCE);
error = dpm_suspend_start(PMSG_HIBERNATE);
error = dpm_suspend_start(PMSG_SUSPEND);