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, 4 insertions, 4 deletions

diff --git a/drivers/net/wireless/ath/ath6kl/cfg80211.c b/drivers/net/wireless/ath/ath6kl/cfg80211.c
index 5dab4f20146a..4a880b4dda5b 100644
--- a/drivers/net/wireless/ath/ath6kl/cfg80211.c
+++ b/drivers/net/wireless/ath/ath6kl/cfg80211.c
@@ -1320,9 +1320,9 @@ static int ath6kl_cfg80211_del_iface(struct wiphy *wiphy,
 	struct ath6kl *ar = wiphy_priv(wiphy);
 	struct ath6kl_vif *vif = netdev_priv(ndev);
 
-	spin_lock(&ar->list_lock);
+	spin_lock_bh(&ar->list_lock);
 	list_del(&vif->list);
-	spin_unlock(&ar->list_lock);
+	spin_unlock_bh(&ar->list_lock);
 
 	ath6kl_cleanup_vif(vif, test_bit(WMI_READY, &ar->flag));
 
@@ -2437,9 +2437,9 @@ struct net_device *ath6kl_interface_add(struct ath6kl *ar, char *name,
 	if (type == NL80211_IFTYPE_ADHOC)
 		ar->ibss_if_active = true;
 
-	spin_lock(&ar->list_lock);
+	spin_lock_bh(&ar->list_lock);
 	list_add_tail(&vif->list, &ar->vif_list);
-	spin_unlock(&ar->list_lock);
+	spin_unlock_bh(&ar->list_lock);
 
 	return ndev;