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Date: Sat, 24 Feb 2024 14:29:05 +0530
From: Siddharth Vadapalli <s-vadapalli@ti.com>
To: Roger Quadros <rogerq@kernel.org>
CC: Chintan Vankar <c-vankar@ti.com>,
        Dan Carpenter
	<dan.carpenter@linaro.org>,
        Siddharth Vadapalli <s-vadapalli@ti.com>,
        Richard
 Cochran <richardcochran@gmail.com>,
        Paolo Abeni <pabeni@redhat.com>, Jakub
 Kicinski <kuba@kernel.org>,
        Eric Dumazet <edumazet@google.com>,
        "David S.
 Miller" <davem@davemloft.net>,
        <linux-kernel@vger.kernel.org>, <netdev@vger.kernel.org>,
        Pekka Varis <p-varis@ti.com>
Subject: Re: [PATCH net-next 2/2] net: ethernet: ti: am65-cpsw: Enable RX HW
 timestamp only for PTP packets
Message-ID: <03d53049-e649-4714-8ad4-49619a5e9475@ti.com>
References: <20240215110953.3225099-1-c-vankar@ti.com>
 <20240215110953.3225099-2-c-vankar@ti.com>
 <4c82705d-b05c-4ee8-88ed-42f944a023ac@kernel.org>
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In-Reply-To: <4c82705d-b05c-4ee8-88ed-42f944a023ac@kernel.org>

On Mon, Feb 19, 2024 at 12:59:55PM +0200, Roger Quadros wrote:
> Hi,
> 
> On 15/02/2024 13:09, Chintan Vankar wrote:
> > The CPSW peripherals on J7AHP, J7VCL, J7AEP, J7ES, AM64 SoCs have
> > an errata i2401 "CPSW: Host Timestamps Cause CPSW Port to Lock up".
> 
..

> >  
> > @@ -856,6 +852,9 @@ static int am65_cpsw_nuss_rx_packets(struct am65_cpsw_common *common,
> >  		ndev_priv = netdev_priv(ndev);
> >  		am65_cpsw_nuss_set_offload_fwd_mark(skb, ndev_priv->offload_fwd_mark);
> >  		skb_put(skb, pkt_len);
> > +		skb_reset_mac_header(skb);
> 
> Why do you need to add skb_reset_mac_header here?
> 
> > +		if (port->rx_ts_enabled)
> > +			am65_cpts_rx_timestamp(common->cpts, skb);
> 
> The timestamp should be added before you do skb_put().

Roger,

Could you please clarify why the timestamp should be added before
skb_put()?

Regards,
Siddharth.