Re: [PATCH] dt-bindings: usb: gpio-sbu-mux: Add an entry for TMUXHS4212

Nishanth Menon
2024-05-20T12:14:56Z

On 08:53-20240520, Krzysztof Kozlowski wrote:
> On 19/05/2024 22:27, Francesco Dolcini wrote:

[...]
> > If it's not the case we'll send the patch later on, however some
> > DT files maintainers (e.g. arch/arm64/boot/dts/ti/) have a policy to
> > just accept DT file in which the binding changes are already merged
> > therefore I was trying to be a little bit proactive here.
>
> TI? Never heard something like this from them... Such requirement would
> seriously slow down any work, so it's not really reasonable. Expectation
> is to post both binding change and an user, so DTS, in case of USB in
> separate patchsets.

There is a reason we have set that "soft rule":
- Driver subsystem merges have known to be broken from time to time and
the dt maintainer is left holding compatibles that have not made to
master.
- ARM subsystem merges prefers not to see checkpatch warnings -
typically, this happens with new compatibles in the driver subsystem.
- Off chance that driver subsystem maintainer picks up the dt changes as
well (should not happen, but has happened)

We have however flexed the rule when:
a) driver maintainer is willing to provide us an immutable tag that we
can merge in and base the dts on top.
b) We felt that the chances of the driver not making it is very very low
(typically after 1+ month in next) and the dts change is in the wider
interest of the community. In such case, we have to explicitly take
the action of letting the patch submitter, driver subsystem to let us
know if something bad happens to the PR, also in our PR to SoC
maintainers, we have to call it out along with rationale why this is
OK. This is a bunch of work from a lot of folks, so prefer only to
trigger this path in case of exceptional cases - there have been a
few far in between.

Again, the default rule (driver in one window, binding in next) has
kept us out of trouble for a few years now at the detriment of pace
of merges, but that took care of a lot of conflicts that we had seen
during initial days of k3 - there are few chains in the lakml list
where this was the direction we ended up in after discussion.

But, yes - as you mentioned, send the patches of the "user" of the dt
binding and driver gives the subsystem and dt maintainers a chance to
review in the context of usage prior to the driver and binding merge.

--
Regards,
Nishanth Menon
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