[PATCH 3/3] ath9k: Use mutex_lock to avoid potential race in start/stop rng

[miaoqing@xxxxxxxxxxxxxx]

From: Miaoqing Pan <miaoqing@xxxxxxxxxxxxxx>

Move ath9k_rng_stop/ath9k_rng_start pair into critical section,
use mutex_lock to void potential race accessing.

Signed-off-by: Miaoqing Pan <miaoqing@xxxxxxxxxxxxxx>
---
 drivers/net/wireless/ath/ath9k/main.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 9e65d14..8b4ac7f 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -731,12 +731,12 @@ static int ath9k_start(struct ieee80211_hw *hw)
 
 	spin_unlock_bh(&sc->sc_pcu_lock);
 
+	ath9k_rng_start(sc);
+
 	mutex_unlock(&sc->mutex);
 
 	ath9k_ps_restore(sc);
 
-	ath9k_rng_start(sc);
-
 	return 0;
 }
 
@@ -826,10 +826,10 @@ static void ath9k_stop(struct ieee80211_hw *hw)
 
 	ath9k_deinit_channel_context(sc);
 
-	ath9k_rng_stop(sc);
-
 	mutex_lock(&sc->mutex);
 
+	ath9k_rng_stop(sc);
+
 	ath_cancel_work(sc);
 
 	if (test_bit(ATH_OP_INVALID, &common->op_flags)) {
-- 
1.9.1