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From:   Andy Shevchenko <andy.shevchenko@gmail.com>
Date:   Mon, 20 Apr 2020 12:44:51 +0300
Message-ID: <CAHp75VeOH+DC362tsEo13gr9fJpeCHXok=7O19B3njbxCOzd2A@mail.gmail.com>
Subject: Re: [PATCH v2 2/2] mtd: rawnand: Add NAND controller support on Intel
 LGM SoC
To:     Boris Brezillon <boris.brezillon@collabora.com>
Cc:     Andy Shevchenko <andriy.shevchenko@intel.com>,
        "Ramuthevar,Vadivel MuruganX" 
        <vadivel.muruganx.ramuthevar@linux.intel.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        "open list:MEMORY TECHNOLOGY..." <linux-mtd@lists.infradead.org>,
        devicetree <devicetree@vger.kernel.org>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        Vignesh R <vigneshr@ti.com>, Arnd Bergmann <arnd@arndb.de>,
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        Thomas Gleixner <tglx@linutronix.de>,
        Anders Roxell <anders.roxell@linaro.org>,
        masonccyang@mxic.com.tw, piotrs@cadence.com,
        Rob Herring <robh+dt@kernel.org>, linux-mips@vger.kernel.org,
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        cheol.yong.kim@intel.com
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On Mon, Apr 20, 2020 at 12:21 PM Boris Brezillon
<boris.brezillon@collabora.com> wrote:
> On Mon, 20 Apr 2020 01:20:40 +0300
> Andy Shevchenko <andriy.shevchenko@intel.com> wrote:
> > On Sat, Apr 18, 2020 at 10:55:33AM +0200, Boris Brezillon wrote:
> > > On Fri, 17 Apr 2020 16:21:47 +0800
> > > "Ramuthevar,Vadivel MuruganX"
> > > <vadivel.muruganx.ramuthevar@linux.intel.com> wrote:
> > >
> > > > From: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@linux.intel.com>
> >
> > > > +static const struct of_device_id lgm_nand_match[] = {
> > > > + { .compatible = "intel,lgm-nand", },
> > > > + {}
> > > > +};
> > > > +MODULE_DEVICE_TABLE(of, lgm_nand_match);
> > >
> > > You probably have a missing "depends on OF" in your Kconfig.
> >
> > Since it's using device property API, dependency is not needed.
> >
>
> There's no compile-time dependency, but this driver will be pretty
> useless if all its users have the NAND controller node defined in their
> DT and CONFIG_OF is not enabled.

No, it's not.
See [1] for the details how ACPI may utilize this table.

[1]: https://www.kernel.org/doc/html/latest/firmware-guide/acpi/enumeration.html#device-tree-namespace-link-device-id

> I guess the OF option is selected by
> arches, so explicitly depending on OF is only relevant if you change
> the dependency rules as suggested in my other reply.

-- 
With Best Regards,
Andy Shevchenko