From: Andrew Lunn <andrew@lunn.ch>
To: Naveen Mamindlapalli <naveenm@marvell.com>
Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
pabeni@redhat.com, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, sgoutham@marvell.com,
Subbaraya Sundeep <sbhatta@marvell.com>
Subject: Re: [net PATCH] octeontx2-pf: Reduce minimum mtu size to 60
Date: Thu, 28 Jul 2022 23:57:06 +0200 [thread overview]
Message-ID: <YuMGMiFv8TAiUI11@lunn.ch> (raw)
In-Reply-To: <20220728123812.21974-1-naveenm@marvell.com>
On Thu, Jul 28, 2022 at 06:08:12PM +0530, Naveen Mamindlapalli wrote:
> 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.
Please Cc: the PTP maintainer for changes like this.
I also don't follow your explanation. At least for the original 802.3,
you had to pad packets shorter than 64 bytes, otherwise CSMA/CD did
not work. So i would expect PTP messages should be padded to 64?
Or is you hardware doing the padding wrong, and this is a workaround
for that bug?
Andrew
next prev parent reply other threads:[~2022-07-28 21:57 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-28 12:38 [net PATCH] octeontx2-pf: Reduce minimum mtu size to 60 Naveen Mamindlapalli
2022-07-28 21:57 ` Andrew Lunn [this message]
2022-07-29 9:33 ` Subbaraya Sundeep Bhatta
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YuMGMiFv8TAiUI11@lunn.ch \
--to=andrew@lunn.ch \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=kuba@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=naveenm@marvell.com \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=sbhatta@marvell.com \
--cc=sgoutham@marvell.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).