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From:   Naveen Mamindlapalli <naveenm@marvell.com>
To:     <davem@davemloft.net>, <edumazet@google.com>, <kuba@kernel.org>,
        <pabeni@redhat.com>, <netdev@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <sgoutham@marvell.com>
CC:     Subbaraya Sundeep <sbhatta@marvell.com>
Subject: [net PATCH] octeontx2-pf: Reduce minimum mtu size to 60
Date:   Thu, 28 Jul 2022 18:08:12 +0530
Message-ID: <20220728123812.21974-1-naveenm@marvell.com>
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From: Subbaraya Sundeep <sbhatta@marvell.com>

PTP messages like SYNC, FOLLOW_UP, DELAY_REQ are of size 58 bytes.
Using a minimum packet length as 64 makes NIX to pad 6 bytes of
zeroes while transmission. This is causing latest ptp4l application to
emit errors since length in PTP header and received packet are not same.
Padding upto 3 bytes is fine but more than that makes ptp4l to assume
the pad bytes as a TLV. Hence reduce the size to 60 from 64.

Signed-off-by: Subbaraya Sundeep <sbhatta@marvell.com>
Signed-off-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
---
 drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.h b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.h
index c88e8a436029..fbe62bbfb789 100644
--- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.h
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.h
@@ -21,7 +21,7 @@
 #define OTX2_HEAD_ROOM		OTX2_ALIGN
 
 #define	OTX2_ETH_HLEN		(VLAN_ETH_HLEN + VLAN_HLEN)
-#define	OTX2_MIN_MTU		64
+#define	OTX2_MIN_MTU		60
 
 #define OTX2_MAX_GSO_SEGS	255
 #define OTX2_MAX_FRAGS_IN_SQE	9
-- 
2.16.5