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Date:   Tue, 18 Jul 2023 22:16:37 +0200
From:   Andrew Lunn <andrew@lunn.ch>
To:     Michael Walle <mwalle@kernel.org>
Cc:     Heiner Kallweit <hkallweit1@gmail.com>,
        Russell King <linux@armlinux.org.uk>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Yisen Zhuang <yisen.zhuang@huawei.com>,
        Salil Mehta <salil.mehta@huawei.com>,
        Florian Fainelli <florian.fainelli@broadcom.com>,
        Broadcom internal kernel review list 
        <bcm-kernel-feedback-list@broadcom.com>,
        Marek =?iso-8859-1?Q?Beh=FAn?= <kabel@kernel.org>,
        Xu Liang <lxu@maxlinear.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Simon Horman <simon.horman@corigine.com>
Subject: Re: [PATCH net-next v3 03/11] net: phy: replace is_c45 with
 phy_accces_mode
Message-ID: <16c19cff-cca7-43fa-97a8-c4e74f033b0b@lunn.ch>
References: <20230620-feature-c45-over-c22-v3-0-9eb37edf7be0@kernel.org>
 <20230620-feature-c45-over-c22-v3-3-9eb37edf7be0@kernel.org>
 <509889a3-f633-40b0-8349-9ef378818cc7@lunn.ch>
 <66d9daa106d7840e972dba35914e6983@kernel.org>
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> Maybe we need to clarify what "has c22/c45 registers space" actually
> means. Responds to MII c22/c45 access?

No. That is not what it means to me. Bus transactions and register
spaces are different.

There are C22 registers, and there are C45 registers.

The bus can do C22 transfers, and it can do C45 transfers.

C22 registers can be access using C22 bus transfers.

C45 registers can be accessed using either C45 bus transfers, or
indirectly via C45 over C22 transfers.

Currently, there is no C22 over C45, but given the oddball Realtek PHY
Russell is talking about in an SFP, it might have a proprietary C22
over C45?

     Andrew