From: Andrew Lunn <andrew@lunn.ch>
To: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: "David S. Miller" <davem@davemloft.net>,
netdev@vger.kernel.org, Sekhar Nori <nsekhar@ti.com>,
linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org
Subject: Re: [PATCH] net: ethernet: ti: cpsw: allow to configure min tx packet size
Date: Mon, 26 Nov 2018 03:27:11 +0100 [thread overview]
Message-ID: <20181126022711.GD32164@lunn.ch> (raw)
In-Reply-To: <20181125234315.28313-1-grygorii.strashko@ti.com>
On Sun, Nov 25, 2018 at 05:43:15PM -0600, Grygorii Strashko wrote:
> For proper VLAN packets forwarding CPSW driver uses min tx packet size of
> 64bytes (VLAN_ETH_ZLEN, excluding ETH_FCS) which was corrected by
> commit 9421c9015047 ("net: ethernet: ti: cpsw: fix min eth packet size").
>
> Unfortunately, this breaks some industrial automation protocols, as
> reported by TI customers [1], which can work only with min TX packet size
> from 60 byte (ecluding FCS).
Hi Grygorii
excluding...
> Hence, introduce module boot parameter "tx_packet_min" to allow configure
> min TX packet size at boot time.
Module parameters are generally not liked.
What actually happens here with this lower limit? Does the hardware
send runt packets? Does the protocol actually require runt packets?
I'm just wondering if the module parameter can be avoided by setting
this as the default. But we need to ensure ARP packets, which are
smaller than the minimum MTU are correctly padded.
Thanks
Andrew
next prev parent reply other threads:[~2018-11-26 2:27 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-25 23:43 [PATCH] net: ethernet: ti: cpsw: allow to configure min tx packet size Grygorii Strashko
2018-11-26 2:27 ` Andrew Lunn [this message]
2018-11-28 1:27 ` Grygorii Strashko
2018-11-28 4:49 ` Andrew Lunn
2018-11-28 20:56 ` Grygorii Strashko
2018-11-28 22:02 ` Andrew Lunn
2018-11-28 22:43 ` Grygorii Strashko
2018-11-29 0:28 ` Andrew Lunn
2018-11-29 1:22 ` David Miller
2018-11-29 23:51 ` Grygorii Strashko
2018-11-29 13:05 ` Lad, Prabhakar
2018-11-29 12:24 ` David Laight
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