cfg80211: Separate available antennas for RX and TX

As has been pointed out by Daniel Halperin some devices (e.g. Intel IWL5100)
can only TX from a subset of RX antennas, so use separate availability masks
for RX and TX.
Signed-off-by: NBruno Randolf <br1@einfach.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

include/net/cfg80211.h

@@ -1482,8 +1482,13 @@ struct ieee80211_txrx_stypes {
  *	transmitted through nl80211, points to an array indexed by interface
  *	type
  *
- * @available_antennas: bitmap of antennas which are available to configure.
- *	antenna configuration commands will be rejected unless this is set.
+ * @available_antennas_tx: bitmap of antennas which are available to be
+ *	configured as TX antennas. Antenna configuration commands will be
+ *	rejected unless this or @available_antennas_rx is set.
+ *
+ * @available_antennas_rx: bitmap of antennas which are available to be
+ *	configured as RX antennas. Antenna configuration commands will be
+ *	rejected unless this or @available_antennas_tx is set.
  *
  * @max_remain_on_channel_duration: Maximum time a remain-on-channel operation
  *	may request, if implemented.
@@ -1528,7 +1533,8 @@ struct wiphy {
 
 	u8 max_num_pmkids;
 
-	u32 available_antennas;
+	u32 available_antennas_tx;
+	u32 available_antennas_rx;
 
 	/* If multiple wiphys are registered and you're handed e.g.
 	 * a regular netdev with assigned ieee80211_ptr, you won't

net/wireless/nl80211.c

@@ -605,7 +605,8 @@ static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags,
 	if (dev->wiphy.flags & WIPHY_FLAG_CONTROL_PORT_PROTOCOL)
 		NLA_PUT_FLAG(msg, NL80211_ATTR_CONTROL_PORT_ETHERTYPE);
 
-	if (dev->wiphy.available_antennas && dev->ops->get_antenna) {
+	if ((dev->wiphy.available_antennas_tx ||
+	     dev->wiphy.available_antennas_rx) && dev->ops->get_antenna) {
 		u32 tx_ant = 0, rx_ant = 0;
 		int res;
 		res = dev->ops->get_antenna(&dev->wiphy, &tx_ant, &rx_ant);
@@ -1107,7 +1108,9 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
 	if (info->attrs[NL80211_ATTR_WIPHY_ANTENNA_TX] &&
 	    info->attrs[NL80211_ATTR_WIPHY_ANTENNA_RX]) {
 		u32 tx_ant, rx_ant;
-		if (!rdev->wiphy.available_antennas || !rdev->ops->set_antenna) {
+		if ((!rdev->wiphy.available_antennas_tx &&
+		     !rdev->wiphy.available_antennas_rx) ||
+		    !rdev->ops->set_antenna) {
 			result = -EOPNOTSUPP;
 			goto bad_res;
 		}
@@ -1116,15 +1119,15 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
 		rx_ant = nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_ANTENNA_RX]);
 
 		/* reject antenna configurations which don't match the
-		 * available antenna mask, except for the "all" mask */
-		if ((~tx_ant && (tx_ant & ~rdev->wiphy.available_antennas)) ||
-		    (~rx_ant && (rx_ant & ~rdev->wiphy.available_antennas))) {
+		 * available antenna masks, except for the "all" mask */
+		if ((~tx_ant && (tx_ant & ~rdev->wiphy.available_antennas_tx)) ||
+		    (~rx_ant && (rx_ant & ~rdev->wiphy.available_antennas_rx))) {
 			result = -EINVAL;
 			goto bad_res;
 		}
 
-		tx_ant = tx_ant & rdev->wiphy.available_antennas;
-		rx_ant = rx_ant & rdev->wiphy.available_antennas;
+		tx_ant = tx_ant & rdev->wiphy.available_antennas_tx;
+		rx_ant = rx_ant & rdev->wiphy.available_antennas_rx;
 
 		result = rdev->ops->set_antenna(&rdev->wiphy, tx_ant, rx_ant);
 		if (result)