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Date:   Wed, 15 Jun 2022 22:07:34 +0200
From:   Andrew Lunn <andrew@lunn.ch>
To:     Jakub Kicinski <kuba@kernel.org>
Cc:     Oleksij Rempel <o.rempel@pengutronix.de>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Paolo Abeni <pabeni@redhat.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Michal Kubecek <mkubecek@suse.cz>, kernel@pengutronix.de,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH net-next v1 1/1] net: phy: add remote fault support
Message-ID: <Yqo8BuxL+XKw8U+a@lunn.ch>
References: <20220608093403.3999446-1-o.rempel@pengutronix.de>
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 <20220614220948.5f0b4827@kernel.org>
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On Tue, Jun 14, 2022 at 10:09:48PM -0700, Jakub Kicinski wrote:
> On Wed, 15 Jun 2022 05:37:46 +0200 Andrew Lunn wrote:
> > > Does this dovetail well with ETHTOOL_A_LINKSTATE_EXT_STATE /
> > > ETHTOOL_A_LINKSTATE_EXT_SUBSTATE ?
> > > 
> > > That's where people who read extended link state out of FW put it
> > > (and therefore it's read only now).  
> > 
> > I did wonder about that. But this is to do with autoneg which is part
> > of ksetting. Firmware hindered MAC drivers also support ksetting
> > set/get.  This patchset is also opening the door to more information
> > which is passed via autoneg. It can also contain the ID the link peer
> > PHY, etc. This is all part of 802.3, where as
> > ETHTOOL_A_LINKSTATE_EXT_STATE tends to be whatever the firmware
> > offers, not something covered by a standard.
> 
> I see, yeah, I think you're right.
> 
> But I'm missing the bigger picture. I'm unclear on who is supposed 
> to be setting the fault user space or kernel / device?

It is also a bit unclear, but at the moment, i think user
space. However, i can see the kernel making use of maybe RF TEST to
ask the link peer to go quiet in order to perform a cable test.

Oleksij, what are your use cases? Maybe add something to patch 0/X
indicating how you plan to make use of this?

	 Andrew