From e38c4be3b2ef3cc240450b27b6df3f35a4be3d3a Mon Sep 17 00:00:00 2001

From: Stephane Graber <stgraber@ubuntu.com>

Date: Tue, 22 Mar 2022 18:42:06 -0400

Subject: [PATCH 7/8] drivers: net: xgene: Fix regression in CRC stripping

Git-commit: e9e6faeafaa00da1851bcf47912b0f1acae666b4

Patch-mainline: v5.18-rc1

References: git-fixes

All packets on ingress (except for jumbo) are terminated with a 4-bytes

CRC checksum. It's the responsability of the driver to strip those 4

bytes. Unfortunately a change dating back to March 2017 re-shuffled some

code and made the CRC stripping code effectively dead.

This change re-orders that part a bit such that the datalen is

immediately altered if needed.

Fixes: 4902a92270fb ("drivers: net: xgene: Add workaround for errata 10GE_8/ENET_11")

Cc: stable@vger.kernel.org

Signed-off-by: Stephane Graber <stgraber@ubuntu.com>

Tested-by: Stephane Graber <stgraber@ubuntu.com>

Link: https://lore.kernel.org/r/20220322224205.752795-1-stgraber@ubuntu.com

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Signed-off-by: Denis Kirjanov <denis.kirjanov@suse.com>

---

 drivers/net/ethernet/apm/xgene/xgene_enet_main.c | 12 +++++++-----

 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/apm/xgene/xgene_enet_main.c b/drivers/net/ethernet/apm/xgene/xgene_enet_main.c

index 2123046fd853..4f7ef1dceba5 100644

--- a/drivers/net/ethernet/apm/xgene/xgene_enet_main.c

+++ b/drivers/net/ethernet/apm/xgene/xgene_enet_main.c

@@ -710,6 +710,12 @@ static int xgene_enet_rx_frame(struct xgene_enet_desc_ring *rx_ring,

 	buf_pool->rx_skb[skb_index] = NULL;

 	datalen = xgene_enet_get_data_len(le64_to_cpu(raw_desc->m1));

+

+	/* strip off CRC as HW isn't doing this */

+	nv = GET_VAL(NV, le64_to_cpu(raw_desc->m0));

+	if (!nv)

+		datalen -= 4;

+

 	skb_put(skb, datalen);

 	prefetch(skb->data - NET_IP_ALIGN);

 	skb->protocol = eth_type_trans(skb, ndev);

@@ -731,12 +737,8 @@ static int xgene_enet_rx_frame(struct xgene_enet_desc_ring *rx_ring,

 		}

 	}

-	nv = GET_VAL(NV, le64_to_cpu(raw_desc->m0));

-	if (!nv) {

-		/* strip off CRC as HW isn't doing this */

-		datalen -= 4;

+	if (!nv)

 		goto skip_jumbo;

-	}

 	slots = page_pool->slots - 1;

 	head = page_pool->head;

-- 

2.16.4