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From:   Mans Rullgard <mans@mansr.com>
To:     Pantelis Antoniou <pantelis.antoniou@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Vitaly Bordug <vbordug@ru.mvista.com>,
        Dan Malek <dan@embeddededge.com>,
        Joakim Tjernlund <joakim.tjernlund@lumentis.se>,
        Christophe Leroy <christophe.leroy@c-s.fr>,
        linuxppc-dev@lists.ozlabs.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH] net: fs_enet: sync rx dma buffer before reading
Date:   Thu, 19 May 2022 20:24:43 +0100
Message-Id: <20220519192443.28681-1-mans@mansr.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The dma_sync_single_for_cpu() call must precede reading the received
data. Fix this.

Fixes: 070e1f01827c ("net: fs_enet: don't unmap DMA when packet len is below copybreak")
Signed-off-by: Mans Rullgard <mans@mansr.com>
---
 drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c b/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c
index b3dae17e067e..432ce10cbfd0 100644
--- a/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c
+++ b/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c
@@ -240,14 +240,14 @@ static int fs_enet_napi(struct napi_struct *napi, int budget)
 				/* +2 to make IP header L1 cache aligned */
 				skbn = netdev_alloc_skb(dev, pkt_len + 2);
 				if (skbn != NULL) {
+					dma_sync_single_for_cpu(fep->dev,
+						CBDR_BUFADDR(bdp),
+						L1_CACHE_ALIGN(pkt_len),
+						DMA_FROM_DEVICE);
 					skb_reserve(skbn, 2);	/* align IP header */
 					skb_copy_from_linear_data(skb,
 						      skbn->data, pkt_len);
 					swap(skb, skbn);
-					dma_sync_single_for_cpu(fep->dev,
-						CBDR_BUFADDR(bdp),
-						L1_CACHE_ALIGN(pkt_len),
-						DMA_FROM_DEVICE);
 				}
 			} else {
 				skbn = netdev_alloc_skb(dev, ENET_RX_FRSIZE);
-- 
2.35.1