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>
diff --git a/drivers/net/wireless/rt2x00/rt2x00.h b/drivers/net/wireless/rt2x00/rt2x00.h
index db2dc97..8b10ea4 100644
--- a/drivers/net/wireless/rt2x00/rt2x00.h
+++ b/drivers/net/wireless/rt2x00/rt2x00.h
@@ -368,6 +368,12 @@
 #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 c3ee4ec..bd422fd 100644
--- a/drivers/net/wireless/rt2x00/rt2x00mac.c
+++ b/drivers/net/wireless/rt2x00/rt2x00mac.c
@@ -247,6 +247,7 @@
 		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 3b27f6a..898cdd7 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.c
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.c
@@ -128,6 +128,7 @@
 	unsigned int data_length;
 	unsigned int duration;
 	unsigned int residual;
+	unsigned long irqflags;
 
 	memset(txdesc, 0, sizeof(*txdesc));
 
@@ -213,14 +214,14 @@
 	 * 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);
 	}