Re: [PATCH] ARM: dts: exynos: Assign a fixed index to mmc devices on ODROID XU3/4 boards

From: Marek Szyprowski
Date: Wed Nov 04 2020 - 07:24:23 EST


Hi Markus,

On 04.11.2020 11:08, Markus Reichl wrote:
> Recently introduced async probe on mmc devices can shuffle block IDs.
> Pin them to fixed values to ease booting in evironments where UUIDs
> are not practical. Use newly introduced aliases for mmcblk devices from [1].
>
> [1]
> https://patchwork.kernel.org/patch/11747669/

Wow, this is a long standing issue, called by others 'a feature'. Good
that this has been finally solved.

> Signed-off-by: Markus Reichl <m.reichl@xxxxxxxxxxxxx>
> ---
> arch/arm/boot/dts/exynos5422-odroidxu3-common.dtsi | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/arch/arm/boot/dts/exynos5422-odroidxu3-common.dtsi b/arch/arm/boot/dts/exynos5422-odroidxu3-common.dtsi
> index e35af40a55cb..91d2840ac8ca 100644
> --- a/arch/arm/boot/dts/exynos5422-odroidxu3-common.dtsi
> +++ b/arch/arm/boot/dts/exynos5422-odroidxu3-common.dtsi
> @@ -13,6 +13,11 @@
> #include "exynos5422-odroid-core.dtsi"
>
> / {
> + aliases {
> + mmc0 = &mmc_2;
> + mmc1 = &mmc_0;

Frankly, I would keep the MMC numbers the same as in u-boot and
datasheets. 0 for the build-in eMMC and 2 for the SD-card. This would be
much more natural. On the other hand, I would agree to do it differently
only on Odroid HC1/HD2/MC1, which don't have build-in eMMC - just use 0
there for the SD-card.

> + };
> +
> gpio-keys {
> compatible = "gpio-keys";
> pinctrl-names = "default";

Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland