From: Andrew Lunn <andrew@lunn.ch>
To: Mason <slash.tmp@free.fr>
Cc: netdev <netdev@vger.kernel.org>, Mans Rullgard <mans@mansr.com>,
Florian Fainelli <f.fainelli@gmail.com>,
Thibaud Cornic <thibaud_cornic@sigmadesigns.com>
Subject: Re: Setting link down or up in software
Date: Thu, 12 Jan 2017 16:28:56 +0100 [thread overview]
Message-ID: <20170112152856.GL13033@lunn.ch> (raw)
In-Reply-To: <2044a26f-cf95-ac55-6265-ac76c3ca53f6@free.fr>
> Here's an example of "Link is Down" printed when I set link up:
>
> At [ 62.750220] I run ip link set dev eth0 down
> Then leave the system idle for 10 minutes.
> At [ 646.263041] I run ip link set dev eth0 up
> At [ 647.364079] it prints "Link is Down"
> At [ 649.417434] it prints "Link is Up - 1Gbps/Full - flow control rx/tx"
Purely a guess, but when you up the interface, it starts auto
negotiation. That often involves resetting the PHY. If the PHY has
already once completed autoneg, e.g. because of the boot loader, it
will be initially UP. The reset will put it DOWN, and then once
autoneg is complete, it will be Up again.
Pure guess. Go read the code and see if i'm write.
Andrew
next prev parent reply other threads:[~2017-01-12 15:28 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-12 13:05 Setting link down or up in software Mason
2017-01-12 15:16 ` Mason
2017-01-12 15:28 ` Andrew Lunn [this message]
2017-01-12 16:22 ` Mason
2017-01-12 16:27 ` Andrew Lunn
2017-01-12 18:45 ` Dan Williams
2017-01-13 9:20 ` Zefir Kurtisi
2017-01-13 15:17 ` Mason
2017-01-13 16:28 ` Zefir Kurtisi
2017-01-13 17:35 ` Mason
2017-01-18 10:29 ` Zefir Kurtisi
2017-01-19 15:40 ` Mason
2017-01-19 17:56 ` Måns Rullgård
2017-01-19 17:59 ` Florian Fainelli
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=20170112152856.GL13033@lunn.ch \
--to=andrew@lunn.ch \
--cc=f.fainelli@gmail.com \
--cc=mans@mansr.com \
--cc=netdev@vger.kernel.org \
--cc=slash.tmp@free.fr \
--cc=thibaud_cornic@sigmadesigns.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).