ath9k: Use atomic operations

The 'sc_flags' variable is being used in a number of places
with no locking whatsoever. This patch converts the usage
of sc_flags to atomic ops.

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -604,12 +604,14 @@ void ath_ant_comb_update(struct ath_softc *sc);
 #define ATH_TXPOWER_MAX         100     /* .5 dBm units */
 #define ATH_RATE_DUMMY_MARKER   0
 
-#define SC_OP_INVALID                BIT(0)
-#define SC_OP_BEACONS                BIT(1)
-#define SC_OP_RXFLUSH                BIT(2)
-#define SC_OP_TSF_RESET              BIT(3)
-#define SC_OP_ANI_RUN                BIT(4)
-#define SC_OP_PRIM_STA_VIF           BIT(5)
+enum sc_op_flags {
+	SC_OP_INVALID,
+	SC_OP_BEACONS,
+	SC_OP_RXFLUSH,
+	SC_OP_TSF_RESET,
+	SC_OP_ANI_RUN,
+	SC_OP_PRIM_STA_VIF,
+};
 
 /* Powersave flags */
 #define PS_WAIT_FOR_BEACON        BIT(0)
@@ -655,9 +657,9 @@ struct ath_softc {
 	struct completion paprd_complete;
 
 	unsigned int hw_busy_count;
+	unsigned long sc_flags;
 
 	u32 intrstatus;
-	u32 sc_flags; /* SC_OP_* */
 	u16 ps_flags; /* PS_* */
 	u16 curtxpow;
 	bool ps_enabled;