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Date:   Thu, 15 Jul 2021 16:12:51 +0300
From:   Vladimir Oltean <olteanv@gmail.com>
To:     Lino Sanfilippo <LinoSanfilippo@gmx.de>
Cc:     Andrew Lunn <andrew@lunn.ch>, woojung.huh@microchip.com,
        UNGLinuxDriver@microchip.com, vivien.didelot@gmail.com,
        f.fainelli@gmail.com, davem@davemloft.net, kuba@kernel.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] net: dsa: tag_ksz: dont let the hardware process the
 layer 4 checksum
Message-ID: <20210715131251.zhtcsjkat267yrtl@skbuf>
References: <20210714191723.31294-1-LinoSanfilippo@gmx.de>
 <20210714191723.31294-3-LinoSanfilippo@gmx.de>
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 <YO9F2LhTizvr1l11@lunn.ch>
 <20210715065455.7nu7zgle2haa6wku@skbuf>
 <trinity-84a570e8-7b5f-44f7-b10c-169d4307d653-1626347772540@3c-app-gmx-bap31>
 <20210715114908.ripblpevmdujkf2m@skbuf>
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On Thu, Jul 15, 2021 at 03:04:31PM +0200, Lino Sanfilippo wrote:
> Please note that skb_put() asserts that the SKB is linearized. So I think we
> should rather clear both NETIF_F_FRAGLIST and NETIF_F_SG unconditionally since also
> header taggers use some form of skb_put() dont they?

The tail taggers use skb_put() as part of the routine to make room for
the tail tag.

Some of the header taggers use __skb_put_padto() when the packets are
too small (under ETH_ZLEN). When they are so small they are definitely
linear already.

We don't have a third form/use of skb_put().