iwlwifi: dvm: don't send zeroed LQ cmd

When the stations are being restored because of unassoc
RXON, the LQ cmd may not have been initialized because it
is initialized only after association.
Sending zeroed LQ_CMD makes the fw unhappy: it raises
SYSASSERT_2078.

Cc: stable@vger.kernel.org
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Reviewed-by: NJohannes Berg <johannes.berg@intel.com>
[move zero_lq and make static const]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

drivers/net/wireless/iwlwifi/dvm/sta.c

@@ -695,6 +695,7 @@ void iwl_clear_ucode_stations(struct iwl_priv *priv,
 void iwl_restore_stations(struct iwl_priv *priv, struct iwl_rxon_context *ctx)
 {
 	struct iwl_addsta_cmd sta_cmd;
+	static const struct iwl_link_quality_cmd zero_lq = {};
 	struct iwl_link_quality_cmd lq;
 	int i;
 	bool found = false;
@@ -733,7 +734,9 @@ void iwl_restore_stations(struct iwl_priv *priv, struct iwl_rxon_context *ctx)
 				else
 					memcpy(&lq, priv->stations[i].lq,
 					       sizeof(struct iwl_link_quality_cmd));
-				send_lq = true;
+
+				if (!memcmp(&lq, &zero_lq, sizeof(lq)))
+					send_lq = true;
 			}
 			spin_unlock_bh(&priv->sta_lock);
 			ret = iwl_send_add_sta(priv, &sta_cmd, CMD_SYNC);