ath5k: claim support for IBSS RSN

Disable group keys programming when using IBSS RSN. Keys will be managed using
software. In this way IBSS RSN can correctly work.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath5k/mac80211-ops.c b/drivers/net/wireless/ath/ath5k/mac80211-ops.c
index 6ed4c07..af4c7ec 100644
--- a/drivers/net/wireless/ath/ath5k/mac80211-ops.c
+++ b/drivers/net/wireless/ath/ath5k/mac80211-ops.c
@@ -483,6 +483,14 @@
 	if (ath5k_modparam_nohwcrypt)
 		return -EOPNOTSUPP;
 
+	if (vif->type == NL80211_IFTYPE_ADHOC &&
+	    (key->cipher == WLAN_CIPHER_SUITE_TKIP ||
+	     key->cipher == WLAN_CIPHER_SUITE_CCMP) &&
+	    !(key->flags & IEEE80211_KEY_FLAG_PAIRWISE)) {
+		/* don't program group keys when using IBSS_RSN */
+		return -EOPNOTSUPP;
+	}
+
 	switch (key->cipher) {
 	case WLAN_CIPHER_SUITE_WEP40:
 	case WLAN_CIPHER_SUITE_WEP104: