ath6kl: Fix lockdep warning

The following is the lockdep warning which detects possible
deadlock condition with the way ar->lock and ar->list_lock
are being used.

  (&(&ar->lock)->rlock){+.-...}, at: [<ffffffffa0492d13>] ath6kl_indicate_tx_activity+0x83/0x110 [ath6kl]
 but this lock took another, SOFTIRQ-unsafe lock in the past:
  (&(&ar->list_lock)->rlock){+.+...}

 and interrupts could create inverse lock ordering between them.

 other info that might help us debug this:
  Possible interrupt unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&(&ar->list_lock)->rlock);
                                local_irq_disable();
                                lock(&(&ar->lock)->rlock);
                                lock(&(&ar->list_lock)->rlock);
   <Interrupt>
     lock(&(&ar->lock)->rlock);

  *** DEADLOCK ***

softirqs have to be disabled when acquiring ar->list_lock to avoid
the above deadlock condition. When the above warning printed the
interface is still up and running without issue.

Reported-by: Kalle Valo <kvalo@qca.qualcomm.com>
Signed-off-by: Vasanthakumar Thiagarajan <vthiagar@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

1 files changed, 7 insertions, 7 deletions

diff --git a/drivers/net/wireless/ath/ath6kl/txrx.c b/drivers/net/wireless/ath/ath6kl/txrx.c
index 9dfd7f5..06e4912 100644
--- a/drivers/net/wireless/ath/ath6kl/txrx.c
+++ b/drivers/net/wireless/ath/ath6kl/txrx.c
@@ -470,10 +470,10 @@ enum htc_send_full_action ath6kl_tx_queue_full(struct htc_target *target,
 
 stop_adhoc_netq:
 	/* FIXME: Locking */
-	spin_lock(&ar->list_lock);
+	spin_lock_bh(&ar->list_lock);
 	list_for_each_entry(vif, &ar->vif_list, list) {
 		if (vif->nw_type == ADHOC_NETWORK) {
-			spin_unlock(&ar->list_lock);
+			spin_unlock_bh(&ar->list_lock);
 
 			spin_lock_bh(&vif->if_lock);
 			set_bit(NETQ_STOPPED, &vif->flags);
@@ -483,7 +483,7 @@ stop_adhoc_netq:
 			return action;
 		}
 	}
-	spin_unlock(&ar->list_lock);
+	spin_unlock_bh(&ar->list_lock);
 
 	return action;
 }
@@ -637,16 +637,16 @@ void ath6kl_tx_complete(void *context, struct list_head *packet_queue)
 	__skb_queue_purge(&skb_queue);
 
 	/* FIXME: Locking */
-	spin_lock(&ar->list_lock);
+	spin_lock_bh(&ar->list_lock);
 	list_for_each_entry(vif, &ar->vif_list, list) {
 		if (test_bit(CONNECTED, &vif->flags) &&
 		    !flushing[vif->fw_vif_idx]) {
-			spin_unlock(&ar->list_lock);
+			spin_unlock_bh(&ar->list_lock);
 			netif_wake_queue(vif->ndev);
-			spin_lock(&ar->list_lock);
+			spin_lock_bh(&ar->list_lock);
 		}
 	}
-	spin_unlock(&ar->list_lock);
+	spin_unlock_bh(&ar->list_lock);
 
 	if (wake_event)
 		wake_up(&ar->event_wq);