On 24/08/2016 10:32, Arnd Bergmann wrote:

I think the ideal is to have only one set of conditionals in each
driver, so at least you don't get a mismatch between them.

SIMPLE_DEV_PM_OPS uses conditional evaluation (but does not
show the reference to the compiler). Annotating the functions as
__maybe_unused lets the compiler decide for itself if they should
be dropped or not, which means we use only the conditional inside
of SIMPLE_DEV_PM_OPS.

Ideally, SIMPLE_DEV_PM_OPS itself should have used an IS_ENABLED()
check instead of the #ifdef, that would have made it possible to
just leave the function always defined with no __maybe_unused, but
still have it dropped from the object code without a warning
when there is no runtime reference.

I'm not sure my trivial issue deserves this much discussion. I just
want the patch to be upstream in some form.

I'll submit one more patch, with SIMPLE_DEV_PM_OPS used unconditionally,
and annotate the resume function with __maybe_unused.

This will waste the space of the struct on systems where S3 is disabled,
but it seems to be the preferred solution, IIUC.

Regards.