target/linux/layerscape/patches-5.4/701-net-0035-sdk_dpaa-accept-frames-on-RX-even-if-larger-than-MTU.patch

From ab1371fec54bdd16b5f6c56c76d817404c696d4b Mon Sep 17 00:00:00 2001
From: Camelia Groza <camelia.groza@nxp.com>
Date: Wed, 18 Oct 2017 16:38:30 +0300
Subject: [PATCH] sdk_dpaa: accept frames on RX even if larger than MTU

Documentation/networking/netdevices.txt mentions that interfaces must
be able to receive frames at least the size of the configured MTU. The
behavior for received frames larger than the MTU is unspecified. We have
been dropping these frames in software. Remove this behavior and accept
them.

Signed-off-by: Camelia Groza <camelia.groza@nxp.com>
---
 drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth.h    | 11 -----------
 drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c | 11 -----------
 2 files changed, 22 deletions(-)

--- a/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth.h
+++ b/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth.h
@@ -514,17 +514,6 @@ dpa_fd_offset(const struct qm_fd *fd)
 	return fd->offset;
 }
 
-/* Verifies if the skb length is below the interface MTU */
-static inline int dpa_check_rx_mtu(struct sk_buff *skb, int mtu)
-{
-	if (unlikely(skb->len > mtu))
-		if ((skb->protocol != htons(ETH_P_8021Q))
-				|| (skb->len > mtu + 4))
-			return -1;
-
-	return 0;
-}
-
 static inline uint16_t dpa_get_headroom(struct dpa_buffer_layout_s *bl)
 {
 	uint16_t headroom;
--- a/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c
+++ b/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c
@@ -616,13 +616,6 @@ void __hot _dpa_rx(struct net_device *ne
 	(*count_ptr)--;
 	skb->protocol = eth_type_trans(skb, net_dev);
 
-	/* IP Reassembled frames are allowed to be larger than MTU */
-	if (unlikely(dpa_check_rx_mtu(skb, net_dev->mtu) &&
-		!(fd_status & FM_FD_IPR))) {
-		percpu_stats->rx_dropped++;
-		goto drop_bad_frame;
-	}
-
 	skb_len = skb->len;
 
 #ifdef CONFIG_FSL_DPAA_DBG_LOOP
@@ -655,10 +648,6 @@ void __hot _dpa_rx(struct net_device *ne
 packet_dropped:
 	return;
 
-drop_bad_frame:
-	dev_kfree_skb(skb);
-	return;
-
 _release_frame:
 	dpa_fd_release(net_dev, fd);
 }