Re: [PATCH] soundwire: Correct ifdef for stub functions

[Charles Keepax]

On Mon, Jun 15, 2026 at 04:05:22PM +0100, Charles Keepax wrote:
> Currently the stubs for SoundWire functions are enabled using
> IS_ENABLED(). The trouble is if a driver intends to use the stubs
> it by definition also does not depend on SOUNDWIRE. This means a
> state can arise where SOUNDWIRE=m and DRIVER_CALLING_STUBS=y,
> leading to a link time failure. Update the stubs to use
> IS_REACHABLE such that the stubs will still be used in the
> above situation.

Feels like maybe I should have noted this can happen say for a
driver that has two control interfaces. For example the rt5682
(in the test robot report) has both an I2C and a SDW. If only the
I2C is selected but the driver calls stubbed functions from
common code. Typically these are gated in some way so they arn't
actually called in the non-soundwire case.

An alternative would be to add a dependency onto the driver to
ensure the two modules are compatible, but this felt like it
would cover more cases.

Thanks,
Charles