Re: [PATCH] arm64: dts: rockchip: aliase sdhci as mmc0 for rk3566 box demo

["Heiko Stübner" <heiko@sntech.de>]

Hi Andy,

Am Samstag, 21. Dezember 2024, 11:49:07 CET schrieb Andy Yan:
> From: Andy Yan <andy.yan@rock-chips.com>
> 
> Follow most others rk356x based boards, and u-boot only use mmc0/1
> as mmc boot targets, so aliase sdhci as mmc0.
> 
> Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
> ---
> 
>  arch/arm64/boot/dts/rockchip/rk3566-box-demo.dts | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/rockchip/rk3566-box-demo.dts b/arch/arm64/boot/dts/rockchip/rk3566-box-demo.dts
> index 41b4cd5a4220..7d0eedf1bd0d 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3566-box-demo.dts
> +++ b/arch/arm64/boot/dts/rockchip/rk3566-box-demo.dts
> @@ -19,9 +19,9 @@ / {
>  
>  	aliases {
>  		ethernet0 = &gmac1;
> -		mmc0 = &sdmmc0;
> -		mmc1 = &sdmmc1;
> -		mmc2 = &sdhci;
> +		mmc0 = &sdhci;
> +		mmc1 = &sdmmc0;
> +		mmc2 = &sdmmc1;

sorry, but that won't be possible :-( .

The original aliases for the mmc order were added over 2 years ago
(november 2022) and became part of the ABI then.

Imagine someone using that board with a rootfs=/dev/mmcblk2p1 part
in the commandline to mount the old sdhci-part1 as rootfs, but now
you reorder the controllers, so so that commandline would try to access
sdmmc1, so their system won't boot anymore after just a simple kernel
update.

Breaking people's setup is one of those big no-go-s in the kernel, so
sadly you'll need to live with the existing order.


Heiko