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From:   Chen-Yu Tsai <wens@csie.org>
Date:   Mon, 19 Apr 2021 11:17:19 +0800
Message-ID: <CAGb2v642Z3iH7fUWa31Rb5j+nWdZ=sXn2BYw3_dyE9P6iuL0Cg@mail.gmail.com>
Subject: Re: [PATCH 0/2] sunxi: Enforce consistent MMC numbering
To:     Samuel Holland <samuel@sholland.org>
Cc:     Maxime Ripard <mripard@kernel.org>,
        Jernej Skrabec <jernej.skrabec@siol.net>,
        devicetree <devicetree@vger.kernel.org>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        linux-sunxi@lists.linux.dev,
        linux-kernel <linux-kernel@vger.kernel.org>
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Hi,

On Mon, Apr 19, 2021 at 10:52 AM Samuel Holland <samuel@sholland.org> wrote:
>
> Dealing with the inconsistent numbering has been a major pain, and
> there is a solution with (as far as I can tell) no tangible downsides.
> So let's use it.
>
> Yes, I know the kernel supports UUIDs for root=. But UUIDs do not help
> when referencing the whole, unpartitioned device, like is needed for
> updating the bootloader and firmware. So for the use case of "write a
> bootloader to the SD card, regardless of where the board is currently
> booted from", I know of two options:
>   - Dig around in sysfs to find the mmc number from the MMIO address,
>     which means I have to know the MMIO addresses for every SoC, or
>   - Apply patches like these.
>
> Samuel Holland (2):
>   ARM: dts: sunxi: h3/h5: Enforce consistent MMC numbering
>   arm64: dts: allwinner: Enforce consistent MMC numbering
>
>  arch/arm/boot/dts/sunxi-h3-h5.dtsi            | 6 ++++++
>  arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi | 6 ++++++
>  arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi  | 6 ++++++

At least with Rockchip this is now done at the board level. IIRC it was
a request from other people to not do it at the SoC level. I don't recall
exactly who though.

ChenYu


>  3 files changed, 18 insertions(+)
>
> --
> 2.26.3
>
>