From: Christian Lamparter Date: Sat, 28 Mar 2009 00:46:14 +0000 (+0100) Subject: ar9170: fix hang on stop X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=32c1628f153a5468cf48be5e5c04cd599ae9e01d;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git 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: Christian Lamparter Signed-off-by: John W. Linville --- diff --git a/drivers/net/wireless/ar9170/main.c b/drivers/net/wireless/ar9170/main.c index 5996ff9f7f47..5f55754d968f 100644 --- a/drivers/net/wireless/ar9170/main.c +++ b/drivers/net/wireless/ar9170/main.c @@ -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)