mac80211: remove dev_hold/put calls

If we move the rcu sections a little, there's
no need to touch the device refcount.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 3ad053f..375cecc 100644 (file)
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1430,8 +1430,6 @@ static void ieee80211_xmit(struct ieee80211_sub_if_data *sdata,
        int headroom;
        bool may_encrypt;
 
-       dev_hold(sdata->dev);
-
        if (need_dynamic_ps(local)) {
                if (local->hw.conf.flags & IEEE80211_CONF_PS) {
                        ieee80211_stop_queues_by_reason(&local->hw,
@@ -1446,6 +1444,8 @@ static void ieee80211_xmit(struct ieee80211_sub_if_data *sdata,
 
        info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
 
+       rcu_read_lock();
+
        if (unlikely(sdata->vif.type == NL80211_IFTYPE_MONITOR)) {
                int hdrlen;
                u16 len_rthdr;
@@ -1468,7 +1468,6 @@ static void ieee80211_xmit(struct ieee80211_sub_if_data *sdata,
                         * support we will need a different mechanism.
                         */
 
-                       rcu_read_lock();
                        list_for_each_entry_rcu(tmp_sdata, &local->interfaces,
                                                list) {
                                if (!netif_running(tmp_sdata->dev))
@@ -1477,13 +1476,10 @@ static void ieee80211_xmit(struct ieee80211_sub_if_data *sdata,
                                        continue;
                                if (compare_ether_addr(tmp_sdata->dev->dev_addr,
                                                       hdr->addr2) == 0) {
-                                       dev_hold(tmp_sdata->dev);
-                                       dev_put(sdata->dev);
                                        sdata = tmp_sdata;
                                        break;
                                }
                        }
-                       rcu_read_unlock();
                }
        }
 
@@ -1497,7 +1493,7 @@ static void ieee80211_xmit(struct ieee80211_sub_if_data *sdata,
 
        if (ieee80211_skb_resize(local, skb, headroom, may_encrypt)) {
                dev_kfree_skb(skb);
-               dev_put(sdata->dev);
+               rcu_read_unlock();
                return;
        }
 
@@ -1508,13 +1504,13 @@ static void ieee80211_xmit(struct ieee80211_sub_if_data *sdata,
                !is_multicast_ether_addr(hdr->addr1))
                        if (mesh_nexthop_lookup(skb, sdata)) {
                                /* skb queued: don't free */
-                               dev_put(sdata->dev);
+                               rcu_read_unlock();
                                return;
                        }
 
        ieee80211_select_queue(local, skb);
        ieee80211_tx(sdata, skb, false);
-       dev_put(sdata->dev);
+       rcu_read_unlock();
 }
 
 netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb,
@@ -1964,12 +1960,10 @@ void ieee80211_tx_pending(unsigned long data)
                        }
 
                        sdata = vif_to_sdata(info->control.vif);
-                       dev_hold(sdata->dev);
                        spin_unlock_irqrestore(&local->queue_stop_reason_lock,
                                                flags);
 
                        txok = ieee80211_tx_pending_skb(local, skb);
-                       dev_put(sdata->dev);
                        if (!txok)
                                __skb_queue_head(&local->pending[i], skb);
                        spin_lock_irqsave(&local->queue_stop_reason_lock,