diff --git a/drivers/net/wireless/ath9k/main.c b/drivers/net/wireless/ath9k/main.c
index e768be4..94c5266 100644
--- a/drivers/net/wireless/ath9k/main.c
+++ b/drivers/net/wireless/ath9k/main.c
@@ -1324,6 +1324,7 @@
 		printk(KERN_ERR "Unable to create debugfs files\n");
 
 	spin_lock_init(&sc->sc_resetlock);
+	mutex_init(&sc->mutex);
 	tasklet_init(&sc->intr_tq, ath9k_tasklet, (unsigned long)sc);
 	tasklet_init(&sc->bcon_tasklet, ath9k_beacon_tasklet,
 		     (unsigned long)sc);
@@ -2133,6 +2134,7 @@
 	struct ath_softc *sc = hw->priv;
 	struct ieee80211_conf *conf = &hw->conf;
 
+	mutex_lock(&sc->mutex);
 	if (changed & (IEEE80211_CONF_CHANGE_CHANNEL |
 		       IEEE80211_CONF_CHANGE_HT)) {
 		struct ieee80211_channel *curchan = hw->conf.channel;
@@ -2145,6 +2147,7 @@
 		if (pos == -1) {
 			DPRINTF(sc, ATH_DBG_FATAL, "Invalid channel: %d\n",
 				curchan->center_freq);
+			mutex_unlock(&sc->mutex);
 			return -EINVAL;
 		}
 
@@ -2165,6 +2168,7 @@
 
 		if (ath_set_channel(sc, &sc->sc_ah->ah_channels[pos]) < 0) {
 			DPRINTF(sc, ATH_DBG_FATAL, "Unable to set channel\n");
+			mutex_unlock(&sc->mutex);
 			return -EINVAL;
 		}
 
@@ -2174,6 +2178,7 @@
 	if (changed & IEEE80211_CONF_CHANGE_POWER)
 		sc->sc_config.txpowlimit = 2 * conf->power_level;
 
+	mutex_unlock(&sc->mutex);
 	return 0;
 }