qede: validate non LSO skb length

Although it is unlikely that stack could transmit a non LSO
skb with length > MTU, however in some cases or environment such
occurrences actually resulted into firmware asserts due to packet
length being greater than the max supported by the device (~9700B).

This patch adds the safeguard for such odd cases to avoid firmware
asserts.

v2: Added "Fixes" tag with one of the initial driver commit
    which enabled the TX traffic actually (as this was probably
    day1 issue which was discovered recently by some customer
    environment)

Fixes: a2ec6172 ("qede: Add support for link")
Signed-off-by: Manish Chopra <manishc@marvell.com>
Signed-off-by: Alok Prasad <palok@marvell.com>
Signed-off-by: Prabhakar Kushwaha <pkushwaha@marvell.com>
Signed-off-by: Ariel Elior <aelior@marvell.com>
Link: https://lore.kernel.org/r/20211203174413.13090-1-manishc@marvell.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/qlogic/qede/qede_fp.c

@@ -1643,6 +1643,13 @@ netdev_tx_t qede_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 			data_split = true;
 		}
 	} else {
+		if (unlikely(skb->len > ETH_TX_MAX_NON_LSO_PKT_LEN)) {
+			DP_ERR(edev, "Unexpected non LSO skb length = 0x%x\n", skb->len);
+			qede_free_failed_tx_pkt(txq, first_bd, 0, false);
+			qede_update_tx_producer(txq);
+			return NETDEV_TX_OK;
+		}
+
 		val |= ((skb->len & ETH_TX_DATA_1ST_BD_PKT_LEN_MASK) <<
 			 ETH_TX_DATA_1ST_BD_PKT_LEN_SHIFT);
 	}