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Commit 32c1628f authored by Christian Lamparter's avatar Christian Lamparter Committed by John W. Linville
Browse files

ar9170: fix hang on stop 



This patch fixes a locking problem which freezes the network core.

The deadlock goes as follows:
- ar9170_op_stop - is called
1. change the state to IDLE
2. > take the MUTEX <
3. cancel_SYNC all pending work, which means
    "block until a work_struct's callback has terminated"
=>  if filter_config_work was queued it tries to get the MUTEX,
       before checking the device state...

Signed-off-by: default avatarChristian Lamparter <chunkeey@web.de>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 807e3739

drivers/net/wireless/ar9170/main.c

+4 −3
Original line number Diff line number Diff line
@@ -742,8 +742,9 @@ static void ar9170_op_stop(struct ieee80211_hw *hw) 
	if (IS_STARTED(ar))

		ar->state = AR9170_IDLE;



	mutex_lock(&ar->mutex);

	flush_workqueue(ar->hw->workqueue);



	mutex_lock(&ar->mutex);

	cancel_delayed_work_sync(&ar->tx_status_janitor);

	cancel_work_sync(&ar->filter_config_work);

	cancel_work_sync(&ar->beacon_work);
@@ -1123,10 +1124,10 @@ static void ar9170_set_filters(struct work_struct *work) 
					 filter_config_work);

	int err;



	mutex_lock(&ar->mutex);

	if (unlikely(!IS_STARTED(ar)))

		goto unlock;

		return ;



	mutex_lock(&ar->mutex);

	if (ar->filter_changed & AR9170_FILTER_CHANGED_PROMISC) {

		err = ar9170_set_operating_mode(ar);

		if (err)