Re: [PATCH v3 0/8] of: property: Make fw_devlink follow GPIO, PWM and clock nexus maps

[Uwe Kleine-König]

On Tue, Oct 20, 2026 at 03:00:11PM +0200, Ernest Van Hoecke wrote:
> This series fixes an fw_devlink supplier-resolution problem reported by
> Leonardo Costa while using a Devicetree nexus to describe GPIO and PWM
> resources routed through an LVDS connector. Consumers referencing the
> nexus could remain deferred because fw_devlink linked them to the nexus
> rather than to the providers selected by gpio-map and pwm-map. [1]
> 
> GPIO, PWM and clock consumer APIs use of_parse_phandle_with_args_map()
> to resolve specifiers through gpio-map, pwm-map and clock-map
> properties. The corresponding fw_devlink parsers use direct phandle
> parsing instead. Given a consumer which references a nexus, the consumer
> API and fw_devlink therefore resolve the reference to different nodes:
> 
>   consumer API:  consumer -> nexus -> mapped provider
>   fw_devlink:    consumer -> nexus
> 
> A nexus is a translation node rather than the resource provider and need
> not have a driver. The link to it can consequently remain unresolved and
> defer the consumer even though the mapped provider is available.
> 
> Make the fw_devlink GPIO, PWM and clock parsers use the same map-aware
> resolver as their consumer APIs. The resolver also handles valid direct
> references by returning the original provider when no map is present.
> Use dedicated exact-name and suffix declaration macros to opt these
> bindings into map-aware parsing without changing unrelated property
> parsers. Retain GPIO's existing exclusions and compatibility handling.
> 
> Since fw_devlink runs the resolver for every consumer when its device is
> created, patch 1 first fixes a stack buffer overflow in the resolver
> when the provider referenced by the consumer has more than
> MAX_PHANDLE_ARGS cells.
> 
> The regression tests call the OF add_links operation and verify that a
> mapped reference creates exactly one link to the provider selected by
> the referenced map entry, not to the nexus. They also cover valid direct
> references. The GPIO tests exercise all property spellings recognized by
> fw_devlink, including the deprecated singular and unprefixed forms.
> 
> The clock patch fixes aacc54c67869 ("clk: Add support for clock nexus dt
> bindings"), which has been in clk-next and linux-next with the same hash
> since next-20260907. There is no build-time dependency on it, but the
> clock patch should not reach mainline before it. The series applies to
> next-20261014.

Acked-by: Uwe Kleine-König <ukleinek@xxxxxxxxxx>

I guess this will be merged via a dt tree and so doesn't need further
action from my side.

Best regards and thanks for caring about this issue,
Uwe

Attachment: signature.asc
Description: PGP signature