Update Linux to v5.4.148

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz

Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/drivers/net/ethernet/ibm/ibmveth.c b/drivers/net/ethernet/ibm/ibmveth.c
index c5be4eb..a20d914 100644
--- a/drivers/net/ethernet/ibm/ibmveth.c
+++ b/drivers/net/ethernet/ibm/ibmveth.c
@@ -1317,6 +1317,7 @@
 			int offset = ibmveth_rxq_frame_offset(adapter);
 			int csum_good = ibmveth_rxq_csum_good(adapter);
 			int lrg_pkt = ibmveth_rxq_large_packet(adapter);
+			__sum16 iph_check = 0;
 
 			skb = ibmveth_rxq_get_buffer(adapter);
 
@@ -1353,16 +1354,26 @@
 			skb_put(skb, length);
 			skb->protocol = eth_type_trans(skb, netdev);
 
+			/* PHYP without PLSO support places a -1 in the ip
+			 * checksum for large send frames.
+			 */
+			if (skb->protocol == cpu_to_be16(ETH_P_IP)) {
+				struct iphdr *iph = (struct iphdr *)skb->data;
+
+				iph_check = iph->check;
+			}
+
+			if ((length > netdev->mtu + ETH_HLEN) ||
+			    lrg_pkt || iph_check == 0xffff) {
+				ibmveth_rx_mss_helper(skb, mss, lrg_pkt);
+				adapter->rx_large_packets++;
+			}
+
 			if (csum_good) {
 				skb->ip_summed = CHECKSUM_UNNECESSARY;
 				ibmveth_rx_csum_helper(skb, adapter);
 			}
 
-			if (length > netdev->mtu + ETH_HLEN) {
-				ibmveth_rx_mss_helper(skb, mss, lrg_pkt);
-				adapter->rx_large_packets++;
-			}
-
 			napi_gro_receive(napi, skb);	/* send it up */
 
 			netdev->stats.rx_packets++;
@@ -1682,7 +1693,7 @@
 	}
 
 	netdev->min_mtu = IBMVETH_MIN_MTU;
-	netdev->max_mtu = ETH_MAX_MTU;
+	netdev->max_mtu = ETH_MAX_MTU - IBMVETH_BUFF_OH;
 
 	memcpy(netdev->dev_addr, mac_addr_p, ETH_ALEN);