[PATCH V2 1/8] PM / Runtime: Fetch runtime PM callbacks using a macro

[Ulf Hansson]

On 27 February 2014 22:25, Alan Stern <stern at rowland.harvard.edu> wrote:
> On Thu, 27 Feb 2014, Ulf Hansson wrote:
>
>> On 27 February 2014 17:22, Alan Stern <stern at rowland.harvard.edu> wrote:
>> > On Thu, 27 Feb 2014, Ulf Hansson wrote:
>> >
>> >> > A reasonable compromise would be to define the macro, and then use it
>> >> > in those three new functions (and nowhere else).
>> >>
>> >> Okay, let me send a v3 that tries this approach then.
>> >>
>> >> >
>> >> > The existing rpm_idle, rpm_suspend, and rpm_resume routines should then
>> >> > be changed to use the new functions.  And of course, the new functions
>> >> > could be called directly by subsystems or PM domains.
>> >>
>> >> Not sure we should export these functions as a part of this patchset.
>> >> Would it not be preferred, to first see if there are any that needs
>> >> it?
>> >
>> > I don't understand.  V2 of the patchset exports
>> > pm_runtime_force_suspend and pm_runtime_force_resume.  Why wouldn't you
>> > want to export them in V3?
>>
>> There are some confusion here. :-)  pm_runtime_force_suspend|resume()
>> surely need to be exported, but that's "patch v2 2/8".
>>
>> I think we were debating whether this patch "patch v2 1/8" should use
>> a macro to walk the ladder to fetch the runtime PM callback - or if we
>> should implement a three c-functions to handle it. I prefer to keep
>> this patch as is, thus using the macro.
>
> But you're going to expand the macro (say, the version that handles
> runtime_resume callbacks) in two places: rpm_resume and
> pm_runtime_force_resume.  That's inefficient.  The macro generates
> fairly complicated code, and so it should be expanded in only one
> place: a single new function.  The new function can be called by both
> rpm_resume and pm_runtime_force_resume.

That's a valid point. Maybe you were trying to tell me this before as
well, not sure.

Anyway, l will send a v3 to address your comments.

Kind regards
Ulf Hansson

>
> In fact, from comparing those two routines, it looks like the new
> function could include a little more than just the macro expansion.
>
> Alan Stern
>