netdev - Re: Cutting the link on ndo_stop - phy_stop or phy

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Message-ID: <20190605084500.pjkq43l4aaepznon@shell.armlinux.org.uk>
Date:   Wed, 5 Jun 2019 09:45:00 +0100
From:   Russell King - ARM Linux admin <linux@...linux.org.uk>
To:     Florian Fainelli <f.fainelli@...il.com>
Cc:     Vladimir Oltean <olteanv@...il.com>,
        Heiner Kallweit <hkallweit1@...il.com>,
        "andrew@...n.ch" <andrew@...n.ch>,
        "netdev@...r.kernel.org" <netdev@...r.kernel.org>,
        Ioana Ciornei <ioana.ciornei@....com>
Subject: Re: Cutting the link on ndo_stop - phy_stop or phy_disconnect?

On Tue, Jun 04, 2019 at 07:25:46PM -0700, Florian Fainelli wrote:
> On 6/4/2019 2:36 PM, Russell King - ARM Linux admin wrote:
> > Normally the PHY receives traffic, and passes it to the MAC which
> > just ignores the signals it receives from the PHY, so no processing
> > beyond the PHY receiving the traffic happens.
> > 
> > Ultimately, whether you want the PHY to stay linked or not linked
> > is, imho, a policy that should be set by the administrator (consider
> > where a system needs to become available quickly after boot vs a
> > system where power saving is important.)  We don't, however, have
> > a facility to specify that policy though.
> 
> Maybe that's what we need, something like:
> 
> ip link set dev eth0 phy [on|off|wake]
> 
> or whatever we deem appropriate such that people willing to maintain the
> PHY on can do that.

How would that work when the PHY isn't bound to the network device until
the network device is brought up?

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
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