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Date:   Wed, 15 Apr 2020 15:45:11 +0200
From:   Andrew Lunn <andrew@lunn.ch>
To:     Oleksij Rempel <o.rempel@pengutronix.de>
Cc:     "David S. Miller" <davem@davemloft.net>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Jonathan Corbet <corbet@lwn.net>,
        Michal Kubecek <mkubecek@suse.cz>,
        David Jander <david@protonic.nl>, kernel@pengutronix.de,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        Russell King <linux@armlinux.org.uk>, mkl@pengutronix.de
Subject: Re: [PATCH v1] ethtool: provide UAPI for PHY master/slave
 configuration.
Message-ID: <20200415134511.GB657811@lunn.ch>
References: <20200415121209.12197-1-o.rempel@pengutronix.de>
 <20200415131104.GA657811@lunn.ch>
 <20200415133728.urvsdolwhaa4eknm@pengutronix.de>
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> In the IEEE 802.3 it is described as:
> ---------------------------------------------------------------------------
> Port type: Bit 9.10 is to be used to indicate the preference to operate
> as MASTER (multiport device) or as SLAVE (single-port device) if the
> MASTER-SLAVE Manual Configuration Enable bit, 9.12, is not set.  Usage
> of this bit is described in 40.5.2.
> 1 = Multiport device
> 0 = single-port device

I really should go read the standard, but...

> ---------------------------------------------------------------------------
> 
> Setting PORT_MODE_MASTER/PORT_MODE_SLAVE will increase the chance to get
> MASTER or SLAVE mode, but not force it.
> 
> If we will follow strictly to the IEEE 802.3 spec, it should be named:
> 
> #define PORT_MODE_UNKNOWN	0x00
> /* this two options will not force some specific mode, only influence
>  * the chance to get it */
> #define PORT_TYPE_MULTI_PORT	0x01
> #define PORT_TYPE_SINGLE_PORT	0x02
> /* this two options will force master or slave mode */
> #define PORT_MODE_MASTER	0x03
> #define PORT_MODE_SLAVE		0x04

I prefer having FORCE in the name.

But let me read the standard and get up to speed.

    Andrew