rt2x00: Sequence counter should be protected in irqsave

The sequence counter can be accessed in IRQ context,
which means the lock protecting the counter should
be irqsave. To prevent making the entire intf->lock irqsave
without reason, create a new lock which only protects
the sequence counter.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 10 insertions, 2 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2x00.h b/drivers/net/wireless/rt2x00/rt2x00.h
index db2dc976d831..8b10ea41b204 100644
--- a/drivers/net/wireless/rt2x00/rt2x00.h
+++ b/drivers/net/wireless/rt2x00/rt2x00.h
@@ -368,6 +368,12 @@ struct rt2x00_intf {
 #define DELAYED_CONFIG_ERP              0x00000002
 #define DELAYED_LED_ASSOC               0x00000004
 
+        /*
+         * Software sequence counter, this is only required
+         * for hardware which doesn't support hardware
+         * sequence counting.
+         */
+        spinlock_t seqlock;
         u16 seqno;
 };
 
diff --git a/drivers/net/wireless/rt2x00/rt2x00mac.c b/drivers/net/wireless/rt2x00/rt2x00mac.c
index c3ee4ecba792..bd422fd6a894 100644
--- a/drivers/net/wireless/rt2x00/rt2x00mac.c
+++ b/drivers/net/wireless/rt2x00/rt2x00mac.c
@@ -247,6 +247,7 @@ int rt2x00mac_add_interface(struct ieee80211_hw *hw,
                 rt2x00dev->intf_sta_count++;
 
         spin_lock_init(&intf->lock);
+        spin_lock_init(&intf->seqlock);
         intf->beacon = entry;
 
         if (conf->type == IEEE80211_IF_TYPE_AP)
diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.c b/drivers/net/wireless/rt2x00/rt2x00queue.c
index 3b27f6aa860c..898cdd7f57d9 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.c
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.c
@@ -128,6 +128,7 @@ static void rt2x00queue_create_tx_descriptor(struct queue_entry *entry,
         unsigned int data_length;
         unsigned int duration;
         unsigned int residual;
+        unsigned long irqflags;
 
         memset(txdesc, 0, sizeof(*txdesc));
 
@@ -213,14 +214,14 @@ static void rt2x00queue_create_tx_descriptor(struct queue_entry *entry,
          * sequence counter given by mac80211.
          */
         if (tx_info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ) {
-                spin_lock(&intf->lock);
+                spin_lock_irqsave(&intf->seqlock, irqflags);
 
                 if (test_bit(ENTRY_TXD_FIRST_FRAGMENT, &txdesc->flags))
                         intf->seqno += 0x10;
                 hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG);
                 hdr->seq_ctrl |= cpu_to_le16(intf->seqno);
 
-                spin_unlock(&intf->lock);
+                spin_unlock_irqrestore(&intf->seqlock, irqflags);
 
                 __set_bit(ENTRY_TXD_GENERATE_SEQ, &txdesc->flags);
         }