ath9k_htc: claim support for IBSS RSN

Skip group keys configuration in hardware in order to make IBSS RSN work.
Keys will be managed using software.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -741,6 +741,8 @@ static void ath9k_set_hw_capab(struct ath9k_htc_priv *priv,
 
 	hw->wiphy->flags &= ~WIPHY_FLAG_PS_ON_BY_DEFAULT;
 
+	hw->wiphy->flags |= WIPHY_FLAG_IBSS_RSN;
+
 	hw->queues = 4;
 	hw->channel_change_time = 5000;
 	hw->max_listen_interval = 10;

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

@@ -1409,6 +1409,21 @@ static int ath9k_htc_set_key(struct ieee80211_hw *hw,
 	if (htc_modparam_nohwcrypt)
 		return -ENOSPC;
 
+	if ((vif->type == NL80211_IFTYPE_ADHOC ||
+	     vif->type == NL80211_IFTYPE_MESH_POINT) &&
+	    (key->cipher == WLAN_CIPHER_SUITE_TKIP ||
+	     key->cipher == WLAN_CIPHER_SUITE_CCMP) &&
+	    !(key->flags & IEEE80211_KEY_FLAG_PAIRWISE)) {
+		/*
+		 * For now, disable hw crypto for the RSN IBSS group keys. This
+		 * could be optimized in the future to use a modified key cache
+		 * design to support per-STA RX GTK, but until that gets
+		 * implemented, use of software crypto for group addressed
+		 * frames is a acceptable to allow RSN IBSS to be used.
+		 */
+		return -EOPNOTSUPP;
+	}
+
 	mutex_lock(&priv->mutex);
 	ath_dbg(common, CONFIG, "Set HW Key\n");
 	ath9k_htc_ps_wakeup(priv);