ath9k: fix channel flag / regd issues with multiple cards

Since the regulatory code touches the channel array, it needs to be
copied for each device instance. That way the original channel array
can also be made const.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Cc: stable@kernel.org [all]
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -56,7 +56,7 @@ MODULE_PARM_DESC(blink, "Enable LED blink on activity");
  * on 5 MHz steps, we support the channels which we know
  * we have calibration data for all cards though to make
  * this static */
-static struct ieee80211_channel ath9k_2ghz_chantable[] = {
+static const struct ieee80211_channel ath9k_2ghz_chantable[] = {
 	CHAN2G(2412, 0), /* Channel 1 */
 	CHAN2G(2417, 1), /* Channel 2 */
 	CHAN2G(2422, 2), /* Channel 3 */
@@ -77,7 +77,7 @@ static struct ieee80211_channel ath9k_2ghz_chantable[] = {
  * on 5 MHz steps, we support the channels which we know
  * we have calibration data for all cards though to make
  * this static */
-static struct ieee80211_channel ath9k_5ghz_chantable[] = {
+static const struct ieee80211_channel ath9k_5ghz_chantable[] = {
 	/* _We_ call this UNII 1 */
 	CHAN5G(5180, 14), /* Channel 36 */
 	CHAN5G(5200, 15), /* Channel 40 */
@@ -477,10 +477,17 @@ static int ath9k_init_queues(struct ath_softc *sc)
 	return -EIO;
 }
 
-static void ath9k_init_channels_rates(struct ath_softc *sc)
+static int ath9k_init_channels_rates(struct ath_softc *sc)
 {
+	void *channels;
+
 	if (test_bit(ATH9K_MODE_11G, sc->sc_ah->caps.wireless_modes)) {
-		sc->sbands[IEEE80211_BAND_2GHZ].channels = ath9k_2ghz_chantable;
+		channels = kmemdup(ath9k_2ghz_chantable,
+			sizeof(ath9k_2ghz_chantable), GFP_KERNEL);
+		if (!channels)
+		    return -ENOMEM;
+
+		sc->sbands[IEEE80211_BAND_2GHZ].channels = channels;
 		sc->sbands[IEEE80211_BAND_2GHZ].band = IEEE80211_BAND_2GHZ;
 		sc->sbands[IEEE80211_BAND_2GHZ].n_channels =
 			ARRAY_SIZE(ath9k_2ghz_chantable);
@@ -490,7 +497,15 @@ static void ath9k_init_channels_rates(struct ath_softc *sc)
 	}
 
 	if (test_bit(ATH9K_MODE_11A, sc->sc_ah->caps.wireless_modes)) {
-		sc->sbands[IEEE80211_BAND_5GHZ].channels = ath9k_5ghz_chantable;
+		channels = kmemdup(ath9k_5ghz_chantable,
+			sizeof(ath9k_5ghz_chantable), GFP_KERNEL);
+		if (!channels) {
+			if (sc->sbands[IEEE80211_BAND_2GHZ].channels)
+				kfree(sc->sbands[IEEE80211_BAND_2GHZ].channels);
+			return -ENOMEM;
+		}
+
+		sc->sbands[IEEE80211_BAND_5GHZ].channels = channels;
 		sc->sbands[IEEE80211_BAND_5GHZ].band = IEEE80211_BAND_5GHZ;
 		sc->sbands[IEEE80211_BAND_5GHZ].n_channels =
 			ARRAY_SIZE(ath9k_5ghz_chantable);
@@ -499,6 +514,7 @@ static void ath9k_init_channels_rates(struct ath_softc *sc)
 		sc->sbands[IEEE80211_BAND_5GHZ].n_bitrates =
 			ARRAY_SIZE(ath9k_legacy_rates) - 4;
 	}
+	return 0;
 }
 
 static void ath9k_init_misc(struct ath_softc *sc)
@@ -594,8 +610,11 @@ static int ath9k_init_softc(u16 devid, struct ath_softc *sc, u16 subsysid,
 	if (ret)
 		goto err_btcoex;
 
+	ret = ath9k_init_channels_rates(sc);
+	if (ret)
+		goto err_btcoex;
+
 	ath9k_init_crypto(sc);
-	ath9k_init_channels_rates(sc);
 	ath9k_init_misc(sc);
 
 	return 0;
@@ -755,6 +774,12 @@ static void ath9k_deinit_softc(struct ath_softc *sc)
 {
 	int i = 0;
 
+	if (sc->sbands[IEEE80211_BAND_2GHZ].channels)
+		kfree(sc->sbands[IEEE80211_BAND_2GHZ].channels);
+
+	if (sc->sbands[IEEE80211_BAND_5GHZ].channels)
+		kfree(sc->sbands[IEEE80211_BAND_5GHZ].channels);
+
         if ((sc->btcoex.no_stomp_timer) &&
 	    sc->sc_ah->btcoex_hw.scheme == ATH_BTCOEX_CFG_3WIRE)
 		ath_gen_timer_free(sc->sc_ah, sc->btcoex.no_stomp_timer);