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From:   Emil Renner Berthing <emil.renner.berthing@canonical.com>
Date:   Thu, 9 Mar 2023 19:19:06 +0100
Message-ID: <CAJM55Z_HGt3iu=trv0v_VzyO3NkVo+aiEaT9vxRURz-MvrbCOg@mail.gmail.com>
Subject: Re: [PATCH v4 12/19] clk: starfive: Add StarFive JH7110 always-on
 clock driver
To:     Conor Dooley <conor@kernel.org>
Cc:     Hal Feng <hal.feng@starfivetech.com>, linux-clk@vger.kernel.org,
        devicetree@vger.kernel.org, linux-riscv@lists.infradead.org,
        Stephen Boyd <sboyd@kernel.org>,
        Michael Turquette <mturquette@baylibre.com>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Ben Dooks <ben.dooks@sifive.com>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Marc Zyngier <maz@kernel.org>, linux-kernel@vger.kernel.org
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On Thu, 9 Mar 2023 at 19:11, Conor Dooley <conor@kernel.org> wrote:
>
> On Thu, Mar 09, 2023 at 03:06:13PM +0100, Emil Renner Berthing wrote:
> >  On Thu, 9 Mar 2023 at 10:44, Hal Feng <hal.feng@starfivetech.com> wrot=
e:
>
> > > The AON clock driver provides clocks for gmac0 which is used frequent=
ly.
> > > So I think it would be more convenient if we set "default y" here.
>
> > You're right that if we default y for the ethernet driver then the aon
> > clock/reset should also default y. Personally I don't think we should
> > default y for every ethernet driver that might be used on some
> > supported risc-v platform, but I see now that
> > arch/riscv/config/defconfig already contains CONFIG_MACB=3Dy,
> > CONFIG_E1000E=3Dy, CONFIG_R8169=3Dy and CONFIG_MICROSEMI_PHY=3Dy, so ma=
ybe
> > I'm wrong or just too late.
>
> The defconfig really needs a good bit of cleanup (one of the many things
> that I am telling myself I will do as part of kconfig.socs cleanup).
>
> w.r.t defconfig Palmer said it pretty well earlier on IRC: "defconfig
> should be useful for kernel devs, which means it should boot on the
> common dev boards".
>
> IMO, that means enough to boot an initramfs and poke the thing to see
> that it is alive, so: ethernet & serial, and the clocks/resets/pinctrl
> stuff required to get those going can all be set to y in defconfig.
>
> In the driver Kconfig entries, to me, it's more or less the same.
> I guess, answer the question "Will your customer's board get to the
> point where it can load a module ithout building this into the kernel?".
> If the answer to that question is yes, then don't make it default y.
>
> That's my =E2=82=AC0.02!

Cool. Defaulting to m in the Kconfig for anything that can be loaded
later is exactly what I was trying to say, except I mixed in the
defconfig for no good reason. That means both the aon clocks and
dwmac-starfive should default to m in Kconfig. The JH7110 (VisionFive
2) boots just fine like that and brings up aon clocks and ethernet
after loading the modules.

/Emil