at76c50x-usb: Make WEP encryption working.

Currently the driver uses HW encryption.
Whenever mac80211 calls the set_key() callback the driver restarts the
whole HW configuration procedure, in order to set (also) the new
WEP key.
However, by doing this, it causes the card to loose association information,
and the HW becomes unable to communicate with the BSS.

This patch adds support for sending another HW command, that sets only
the wep key, instead of resetting all.
Mac80211 key-set requests are thus handled via this new command.

Tested on my at76c503

Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 39 insertions, 1 deletions

diff --git a/drivers/net/wireless/at76c50x-usb.c b/drivers/net/wireless/at76c50x-usb.c
index 9e6e9fc27d6a..10fd12ec85be 100644
--- a/drivers/net/wireless/at76c50x-usb.c
+++ b/drivers/net/wireless/at76c50x-usb.c
@@ -2039,6 +2039,44 @@ static void at76_configure_filter(struct ieee80211_hw *hw,
 	ieee80211_queue_work(hw, &priv->work_set_promisc);
 }
 
+static int at76_set_wep(struct at76_priv *priv)
+{
+	int ret = 0;
+	struct mib_mac_wep *mib_data = &priv->mib_buf.data.wep_mib;
+
+	priv->mib_buf.type = MIB_MAC_WEP;
+	priv->mib_buf.size = sizeof(struct mib_mac_wep);
+	priv->mib_buf.index = 0;
+
+	memset(mib_data, 0, sizeof(*mib_data));
+
+	if (priv->wep_enabled) {
+		if (priv->wep_keys_len[priv->wep_key_id] > WEP_SMALL_KEY_LEN)
+			mib_data->encryption_level = 2;
+		else
+			mib_data->encryption_level = 1;
+
+		/* always exclude unencrypted if WEP is active */
+		mib_data->exclude_unencrypted = 1;
+	} else {
+		mib_data->exclude_unencrypted = 0;
+		mib_data->encryption_level = 0;
+	}
+
+	mib_data->privacy_invoked = priv->wep_enabled;
+	mib_data->wep_default_key_id = priv->wep_key_id;
+	memcpy(mib_data->wep_default_keyvalue, priv->wep_keys,
+	       sizeof(priv->wep_keys));
+
+	ret = at76_set_mib(priv, &priv->mib_buf);
+
+	if (ret < 0)
+		wiphy_err(priv->hw->wiphy,
+			  "set_mib (wep) failed: %d\n", ret);
+
+	return ret;
+}
+
 static int at76_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
 			struct ieee80211_vif *vif, struct ieee80211_sta *sta,
 			struct ieee80211_key_conf *key)
@@ -2081,7 +2119,7 @@ static int at76_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
 			priv->wep_enabled = 1;
 	}
 
-	at76_startup_device(priv);
+	at76_set_wep(priv);
 
 	mutex_unlock(&priv->mtx);