Re: [PATCH] dts: Re-add aliases for imx6qdl-sabrelite devices

Detlev Casanova
2022-12-07T19:53:24Z

On Monday, December 5, 2022 12:33:48 P.M. EST Fabio Estevam wrote:
> On Mon, Dec 5, 2022 at 12:37 PM Tom Rini <trini@konsulko.com> wrote:
> > I'm not really happy with this approach. It's not that upstream doesn't
> > have aliases now, it's that it has different aliases, right? That's why
> > they won't accept these?
>
> imx6q.dtsi does have the default mmc aliases:
>
> mmc0 = &usdhc1;
> mmc1 = &usdhc2;
> mmc2 = &usdhc3;
> mmc3 = &usdhc4;
>
> Upstream does not want to change mmc alias because users may rely on
> this mmc aliases.
>
> Changing it now may cause the board not to boot anymore as the rootfs
> cannot be found.
>
> It is OK to change mmc alias for a newly introduced board, but please
> keep in mind that
> wandboard and sabrelite have been launched many many years ago.
>
> So for upstream Linux the message was clear: don't change the mmc
> alias for these boards.
>
> Now let's talk about U-Boot.
>
> Prior to d0399a46e7cd ("imx6dl/imx6qdl: synchronise device trees with
> linux") the mmc alias for sabrelite was present:
>
> mmc0 = &usdhc3;
> mmc1 = &usdhc4;
>
> After this commit, the mmc alias is gone and causes the boot
> regression as reported by Detlev.
>
> We don't want to cause regressions in U-Boot as well, so that's why I
> propose just adding the alias into u-boot.dtsi.
>
> There are many boards that does the same.
>
> > But this also highlights that we really need to get these kind of
> > aliases and similar (a) re-synced with upstream ASAP and (b) do that at
>
> imx6 dts files are already synced with Linux.
>
> > the start. I don't know which group of "users are broken by this change"
> > is bigger, the group that needs the aliases we have or the group that
> > needs the other aliases, but the group that gets changes upstream first
> > "wins" here is how the OSS world works.
>
> I prefer to not break things for anyone, hence my proposal.
>
> If you are still not happy with it, please feel free to submit a patch
> with your proposal.

There is no SPL enabled for the imx.6 Sabrelite, Isn't that needed to use the
*-u-boot.dtsi files ?

It is not clear to me how those are loaded.

Detlev.