ath9k: rename rxflushlock to pcu_lock

The real way to lock RX is to contend on the PCU
and reset, this will be fixed in the next patch but for
now just do the renames so that the next patch which changes
the locking order is crystal clear.

This is part of a series that will help resolve the bug:

https://bugzilla.kernel.org/show_bug.cgi?id=14624

For more details about this issue refer to:

http://marc.info/?l=linux-wireless&m=128629803703756&w=2

Cc: stable@kernel.org
Cc: Ben Greear <greearb@candelatech.com>
Cc: Kyungwan Nam <kyungwan.nam@atheros.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Tested-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/ath9k.h

@@ -310,7 +310,7 @@ struct ath_rx {
 	u8 rxotherant;
 	u32 *rxlink;
 	unsigned int rxfilter;
-	spinlock_t rxflushlock;
+	spinlock_t pcu_lock;
 	spinlock_t rxbuflock;
 	struct list_head rxbuf;
 	struct ath_descdma rxdma;

drivers/net/wireless/ath/ath9k/main.c

@@ -613,7 +613,7 @@ void ath9k_tasklet(unsigned long data)
 		rxmask = (ATH9K_INT_RX | ATH9K_INT_RXEOL | ATH9K_INT_RXORN);
 
 	if (status & rxmask) {
-		spin_lock_bh(&sc->rx.rxflushlock);
+		spin_lock_bh(&sc->rx.pcu_lock);
 
 		/* Check for high priority Rx first */
 		if ((ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) &&
@@ -621,7 +621,7 @@ void ath9k_tasklet(unsigned long data)
 			ath_rx_tasklet(sc, 0, true);
 
 		ath_rx_tasklet(sc, 0, false);
-		spin_unlock_bh(&sc->rx.rxflushlock);
+		spin_unlock_bh(&sc->rx.pcu_lock);
 	}
 
 	if (status & ATH9K_INT_TX) {

drivers/net/wireless/ath/ath9k/recv.c

@@ -317,7 +317,7 @@ int ath_rx_init(struct ath_softc *sc, int nbufs)
 	struct ath_buf *bf;
 	int error = 0;
 
-	spin_lock_init(&sc->rx.rxflushlock);
+	spin_lock_init(&sc->rx.pcu_lock);
 	sc->sc_flags &= ~SC_OP_RXFLUSH;
 	spin_lock_init(&sc->rx.rxbuflock);
 
@@ -533,13 +533,13 @@ bool ath_stoprecv(struct ath_softc *sc)
 
 void ath_flushrecv(struct ath_softc *sc)
 {
-	spin_lock_bh(&sc->rx.rxflushlock);
+	spin_lock_bh(&sc->rx.pcu_lock);
 	sc->sc_flags |= SC_OP_RXFLUSH;
 	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
 		ath_rx_tasklet(sc, 1, true);
 	ath_rx_tasklet(sc, 1, false);
 	sc->sc_flags &= ~SC_OP_RXFLUSH;
-	spin_unlock_bh(&sc->rx.rxflushlock);
+	spin_unlock_bh(&sc->rx.pcu_lock);
 }
 
 static bool ath_beacon_dtim_pending_cab(struct sk_buff *skb)