Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <21ee77073341cd2b5e0109be5da61d8e981ea50d.camel@redhat.com>
Subject: Re: [PATCH] net: macb: Disable macb pad and fcs for fragmented
 packets
From:   Paolo Abeni <pabeni@redhat.com>
To:     Harini Katakam <harini.katakam@xilinx.com>,
        nicolas.ferre@microchip.com, davem@davemloft.net,
        claudiu.beznea@microchip.com, kuba@kernel.org, dumazet@google.com
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        michal.simek@xilinx.com, harinikatakamlinux@gmail.com,
        radhey.shyam.pandey@xilinx.com
Date:   Tue, 10 May 2022 15:18:32 +0200
In-Reply-To: <20220509121513.30549-1-harini.katakam@xilinx.com>
References: <20220509121513.30549-1-harini.katakam@xilinx.com>
Content-Type: text/plain; charset="UTF-8"
User-Agent: Evolution 3.42.4 (3.42.4-2.fc35) 
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Precedence: bulk

On Mon, 2022-05-09 at 17:45 +0530, Harini Katakam wrote:
> data_len in skbuff represents bytes resident in fragment lists or
> unmapped page buffers. For such packets, when data_len is non-zero,
> skb_put cannot be used - this will throw a kernel bug. Hence do not
> use macb_pad_and_fcs for such fragments.
> 
> Signed-off-by: Harini Katakam <harini.katakam@xilinx.com>
> Signed-off-by: Michal Simek <michal.simek@xilinx.com>
> Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>

This looks like a fix suitable for the net tree. Please add a relevant
'Fixes' tag.

> ---
>  drivers/net/ethernet/cadence/macb_main.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
> index 6434e74c04f1..0b03305ad6a0 100644
> --- a/drivers/net/ethernet/cadence/macb_main.c
> +++ b/drivers/net/ethernet/cadence/macb_main.c
> @@ -1995,7 +1995,8 @@ static unsigned int macb_tx_map(struct macb *bp,
>  			ctrl |= MACB_BF(TX_LSO, lso_ctrl);
>  			ctrl |= MACB_BF(TX_TCP_SEQ_SRC, seq_ctrl);
>  			if ((bp->dev->features & NETIF_F_HW_CSUM) &&
> -			    skb->ip_summed != CHECKSUM_PARTIAL && !lso_ctrl)
> +			    skb->ip_summed != CHECKSUM_PARTIAL && !lso_ctrl &&
> +			    (skb->data_len == 0))
>  				ctrl |= MACB_BIT(TX_NOCRC);
>  		} else
>  			/* Only set MSS/MFS on payload descriptors

This chunk looks unrelated to the commit message ?!? only the next one
looks relevant.

Thanks.

Paolo