From 32c1628f153a5468cf48be5e5c04cd599ae9e01d Mon Sep 17 00:00:00 2001
From: Christian Lamparter <chunkeey@web.de>
Date: Sat, 28 Mar 2009 01:46:14 +0100
Subject: [PATCH] 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 <chunkeey@web.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
---
drivers/net/wireless/ar9170/main.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
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)
--
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