Hello [...]
- Use raw notifiers protected by spinlocks instead of atomic notifiers
[...]
+/** + * do_kernel_power_off - Execute kernel poweroff handler call chain + * + * Calls functions registered with register_power_off_handler. + * + * Expected to be called from machine_power_off as last step of + * the poweroff sequence. + * + * Powers off the system immediately if a poweroff handler function + * has been registered. Otherwise does nothing. + */ +void do_kernel_power_off(void) +{ + spin_lock(&power_off_handler_lock); + raw_notifier_call_chain(&power_off_handler_list, 0, NULL); + spin_unlock(&power_off_handler_lock); +}
I don't get it. You are still in atomic context inside the poweroff callback since you lock it with a spinlock. It does not change much from the atomic notifier which was doing exactly the same thing but with RCU: rcu_read_lock(); ret = notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls); rcu_read_unlock(); Why not using the blocking_notifier_* family ? It will lock with a read-write semaphore under which you can sleep. For instance, twl4030_power_off will sleep, since it is doing I2C access. So you cannot call it in atomic context. Thanks, Philippe -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/