cxgb4: LE-Workaround is not atomic in firmware

The LE workaround in firmware is not atomic and fw_ofld_connection_wrs must not interleave.
Therefore, when the workaround is enabled, we need to send all ctrlq WRs on a single ctrl queue.

Based on original work by Santosh Rastapur <santosh@chelsio.com>

Signed-off-by: Kumar Sanghvi <kumaras@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/cxgb4/sge.c

@@ -1467,8 +1467,12 @@ static inline int ofld_send(struct adapter *adap, struct sk_buff *skb)
 {
 	unsigned int idx = skb_txq(skb);
 
-	if (unlikely(is_ctrl_pkt(skb)))
+	if (unlikely(is_ctrl_pkt(skb))) {
+		/* Single ctrl queue is a requirement for LE workaround path */
+		if (adap->tids.nsftids)
+			idx = 0;
 		return ctrl_xmit(&adap->sge.ctrlq[idx], skb);
+	}
 	return ofld_xmit(&adap->sge.ofldtxq[idx], skb);
 }