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Date:   Thu, 19 Jul 2018 17:01:38 +0200
From:   Andrew Lunn <andrew@lunn.ch>
To:     Bartosz Golaszewski <brgl@bgdev.pl>
Cc:     Sekhar Nori <nsekhar@ti.com>, Kevin Hilman <khilman@kernel.org>,
        Russell King <linux@armlinux.org.uk>,
        Grygorii Strashko <grygorii.strashko@ti.com>,
        "David S . Miller" <davem@davemloft.net>,
        Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
        Lukas Wunner <lukas@wunner.de>, Rob Herring <robh@kernel.org>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Dan Carpenter <dan.carpenter@oracle.com>,
        Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>,
        David Lechner <david@lechnology.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-omap@vger.kernel.org, netdev@vger.kernel.org,
        Bartosz Golaszewski <bgolaszewski@baylibre.com>
Subject: Re: [PATCH 5/5] net: add MTD support to
 eth_platform_get_mac_address()
Message-ID: <20180719150138.GC9119@lunn.ch>
References: <20180718161035.7005-1-brgl@bgdev.pl>
 <20180718161035.7005-6-brgl@bgdev.pl>
 <20180718164737.GE12477@lunn.ch>
 <CAMRc=MeRv3_C8_R-Awfr1zjLa3G_CVAACc-2t_ihB+1v+BCTGw@mail.gmail.com>
 <20180718170352.GF12477@lunn.ch>
 <CAMRc=Md3oeEktzrA9UZyNPX6pB4bG+Gv0o6cjbs0UUKb3sYTsA@mail.gmail.com>
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On Thu, Jul 19, 2018 at 10:14:29AM +0200, Bartosz Golaszewski wrote:
> 2018-07-18 19:03 GMT+02:00 Andrew Lunn <andrew@lunn.ch>:
> >> >> +#ifdef CONFIG_MTD
> >> >> +     /* NOTE: this should go away as soon as MTD gets nvmem support. */
> >> >> +     if (!addr) {
> >> >> +             struct mtd_info *mtd;
> >> >> +             int rv;
> >> >> +
> >> >> +             mtd = get_mtd_device_nm("MAC-Address");
> >> >
> >> > In order for this to go away, you need to keep backwards
> >> > compatibility. When using nvmem, you look for a cell called
> >> > "mac-address". Here you are looking for "MAC-Address". That is going
> >> > to make backwards compatibility harder. How do you plan to do it?
> >> >
> >> >    Andrew
> >>
> >> I'm trying to adjust to already existing users. The only user of
> >> get_mtd_device_nm() who calls it to read the MAC address registers a
> >> partition called "MAC-Address". We can't change it since it's visible
> >> from user space. In the future we'd just have to have a list of
> >> supported string that we'd use to do the nvmem lookup.
> >
> > Why not have the nvmem cell called "MAC-Address"? When you add nvmem
> > support to MTD, i assume you are going to map each MTD partition to an
> > nvmem cell?
> 
> Because all existing users of nvmem use "mac-address" as the name of
> this cell already. I guess we will need to live with both in this
> particular function.

So i'm not convinced this last patch is making things better. I would
prefer if it was dropped for the moment. Wait until MTD via nvmem is
actually implemented and there is a concrete concept of how a MAC
address would be looked up without having lots of ugly code.

	Andrew