[MAC80211]: improve locking of sta_info related structures

The sta_info code has some awkward locking which prevents some driver
callbacks from being allowed to sleep. This patch makes the locking more
focused so code that calls driver callbacks are allowed to sleep. It also
converts sta_lock to a rwlock.

Signed-off-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: Jiri Benc <jbenc@suse.cz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index dc128b412eab..2a1a7d457136 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -306,7 +306,7 @@ static void purge_old_ps_buffers(struct ieee80211_local *local)
         }
         read_unlock(&local->sub_if_lock);
 
-        spin_lock_bh(&local->sta_lock);
+        read_lock_bh(&local->sta_lock);
         list_for_each_entry(sta, &local->sta_list, list) {
                 skb = skb_dequeue(&sta->ps_tx_buf);
                 if (skb) {
@@ -315,7 +315,7 @@ static void purge_old_ps_buffers(struct ieee80211_local *local)
                 }
                 total += skb_queue_len(&sta->ps_tx_buf);
         }
-        spin_unlock_bh(&local->sta_lock);
+        read_unlock_bh(&local->sta_lock);
 
         local->total_ps_buffered = total;
         printk(KERN_DEBUG "%s: PS buffers full - purged %d frames\n",
@@ -1629,7 +1629,7 @@ static void ieee80211_beacon_add_tim(struct ieee80211_local *local,
 
         /* Generate bitmap for TIM only if there are any STAs in power save
          * mode. */
-        spin_lock_bh(&local->sta_lock);
+        read_lock_bh(&local->sta_lock);
         if (atomic_read(&bss->num_sta_ps) > 0)
                 /* in the hope that this is faster than
                  * checking byte-for-byte */
@@ -1680,7 +1680,7 @@ static void ieee80211_beacon_add_tim(struct ieee80211_local *local,
                 *pos++ = aid0; /* Bitmap control */
                 *pos++ = 0; /* Part Virt Bitmap */
         }
-        spin_unlock_bh(&local->sta_lock);
+        read_unlock_bh(&local->sta_lock);
 }
 
 struct sk_buff *ieee80211_beacon_get(struct ieee80211_hw *hw, int if_id,