wl12xx: Enable beacon early termination in 2.4GHz band only

Beacon early termination doesn't help much in the 5GHz band and masks
channel switch IE Beacons.  Thus, change the code to use BET only in
2.4GHz.

[Reworded the commit log slightly -- Luca.]
Signed-off-by: Shahar Levi <shahar_levi@ti.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>

drivers/net/wireless/wl12xx/event.c

@@ -133,10 +133,13 @@ static int wl1271_event_ps_report(struct wl1271 *wl,
 		if (ret < 0)
 			break;
 
-		/* enable beacon early termination */
-		ret = wl1271_acx_bet_enable(wl, true);
-		if (ret < 0)
-			break;
+		/*
+		 * BET has only a minor effect in 5GHz and masks
+		 * channel switch IEs, so we only enable BET on 2.4GHz
+		*/
+		if (wl->band == IEEE80211_BAND_2GHZ)
+			/* enable beacon early termination */
+			ret = wl1271_acx_bet_enable(wl, true);
 
 		if (wl->ps_compl) {
 			complete(wl->ps_compl);

drivers/net/wireless/wl12xx/ps.c

@@ -169,9 +169,11 @@ int wl1271_ps_set_mode(struct wl1271 *wl, enum wl1271_cmd_ps_mode mode,
 		wl1271_debug(DEBUG_PSM, "leaving psm");
 
 		/* disable beacon early termination */
-		ret = wl1271_acx_bet_enable(wl, false);
-		if (ret < 0)
-			return ret;
+		if (wl->band == IEEE80211_BAND_2GHZ) {
+			ret = wl1271_acx_bet_enable(wl, false);
+			if (ret < 0)
+				return ret;
+		}
 
 		/* disable beacon filtering */
 		ret = wl1271_acx_beacon_filter_opt(wl, false);