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Date:   Tue, 5 Oct 2021 00:01:18 +0200
From:   Andrew Lunn <andrew@lunn.ch>
To:     Sean Anderson <sean.anderson@seco.com>
Cc:     netdev@vger.kernel.org, "David S . Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>, linux-kernel@vger.kernel.org,
        Heiner Kallweit <hkallweit1@gmail.com>,
        Russell King <linux@armlinux.org.uk>
Subject: Re: [RFC net-next PATCH 16/16] net: sfp: Add quirk to ignore PHYs
Message-ID: <YVt5rpEl3HkIkAfB@lunn.ch>
References: <20211004191527.1610759-1-sean.anderson@seco.com>
 <20211004191527.1610759-17-sean.anderson@seco.com>
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On Mon, Oct 04, 2021 at 03:15:27PM -0400, Sean Anderson wrote:
> Some modules have something at SFP_PHY_ADDR which isn't a PHY. If we try to
> probe it, we might attach genphy anyway if addresses 2 and 3 return
> something other than all 1s. To avoid this, add a quirk for these modules
> so that we do not probe their PHY.
> 
> The particular module in this case is a Finisar SFP-GB-GE-T. This module is
> also worked around in xgbe_phy_finisar_phy_quirks() by setting the support
> manually. However, I do not believe that it has a PHY in the first place:
> 
> $ i2cdump -y -r 0-31 $BUS 0x56 w
>      0,8  1,9  2,a  3,b  4,c  5,d  6,e  7,f
> 00: ff01 ff01 ff01 c20c 010c 01c0 0f00 0120
> 08: fc48 000e ff78 0000 0000 0000 0000 00f0
> 10: 7800 00bc 0000 401c 680c 0300 0000 0000
> 18: ff41 0000 0a00 8890 0000 0000 0000 0000
> 
> The first several addresses contain the same value, which should almost
> never be the case for a proper phy. In addition, the "OUI" 00-7F-C3 does
> not match Finisar's OUI of 00-90-65 (or any other OUI for that matter).
> 
> Signed-off-by: Sean Anderson <sean.anderson@seco.com>

Hi Sean

This does not really have anything to do with PCS. I would send it on
its own.

    Andrew