Bluetooth: rfcomm: Remove unnecessary krfcommd event (e5842cdb) · Commits · 戴 / test

Removed superfluous event handling which was used to signal that the rfcomm kthread had been woken. This appears to have been used to prevent lost wakeups. Correctly ordering when the task state is set to TASK_INTERRUPTIBLE is sufficient to prevent lost wakeups. To prevent wakeups which occurred prior to initially setting TASK_INTERRUPTIBLE from being lost, the main work of the thread loop - rfcomm_process_sessions() - is performed prior to sleeping. Signed-off-by:

Peter Hurley <peter@hurleysoftware.com> Signed-off-by:

Gustavo F. Padovan <padovan@profusion.mobi>

net/bluetooth/rfcomm/core.c

+7 −10

Original line number	Diff line number	Diff line
		@@ -62,7 +62,6 @@ static DEFINE_MUTEX(rfcomm_mutex);
		#define rfcomm_lock() mutex_lock(&rfcomm_mutex)
		#define rfcomm_unlock() mutex_unlock(&rfcomm_mutex)

		static unsigned long rfcomm_event;

		static LIST_HEAD(session_list);

		@@ -120,7 +119,6 @@ static inline void rfcomm_schedule(void)
		{
		if (!rfcomm_thread)
		return;
		set_bit(RFCOMM_SCHED_WAKEUP, &rfcomm_event);
		wake_up_process(rfcomm_thread);
		}

		@@ -2038,19 +2036,18 @@ static int rfcomm_run(void *unused)

		rfcomm_add_listener(BDADDR_ANY);

		while (!kthread_should_stop()) {
		while (1) {
		set_current_state(TASK_INTERRUPTIBLE);
		if (!test_bit(RFCOMM_SCHED_WAKEUP, &rfcomm_event)) {
		/* No pending events. Let's sleep.
		* Incoming connections and data will wake us up. */
		schedule();
		}
		set_current_state(TASK_RUNNING);

		if (kthread_should_stop())
		break;

		/* Process stuff */
		clear_bit(RFCOMM_SCHED_WAKEUP, &rfcomm_event);
		rfcomm_process_sessions();

		schedule();
		}
		__set_current_state(TASK_RUNNING);

		rfcomm_kill_listener();

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