On Fri, Apr 9, 2021 at 6:30 AM Arnd Bergmann <arnd@xxxxxxxx> wrote: > > On Thu, Apr 8, 2021 at 11:00 PM Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote: > > > > Drivers typically surround suspend and resume callbacks with #ifdef > > CONFIG_PM(_SLEEP) or mark them as __maybe_unused in order to avoid > > -Wunused-const-variable warnings. > > > > With this commit, drivers will be able to remove #ifdef CONFIG_PM(_SLEEP) > > and __maybe_unsed because unused functions are dropped by the compiler > > instead of the preprocessor. > > > > Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx> > > I tried this before and could not get it to work right. > > > > > -#ifdef CONFIG_PM_SLEEP > > +#define pm_ptr(_ptr) PTR_IF(IS_ENABLED(CONFIG_PM), _ptr) > > +#define pm_sleep_ptr(_ptr) PTR_IF(IS_ENABLED(CONFIG_PM_SLEEP), _ptr) > > + > > #define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \ > > - .suspend = suspend_fn, \ > > - .resume = resume_fn, \ > > - .freeze = suspend_fn, \ > > - .thaw = resume_fn, \ > > - .poweroff = suspend_fn, \ > > - .restore = resume_fn, > > -#else > > -#define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) > > -#endif > > + .suspend = pm_sleep_ptr(suspend_fn), \ > > + .resume = pm_sleep_ptr(resume_fn), \ > > + .freeze = pm_sleep_ptr(suspend_fn), \ > > + .thaw = pm_sleep_ptr(resume_fn), \ > > + .poweroff = pm_sleep_ptr(suspend_fn), \ > > + .restore = pm_sleep_ptr(resume_fn), > > The problem that I think you inevitably hit is that you run into a missing > declaration for any driver that still uses an #ifdef around a static > function. > > The only way I can see us doing this is to create a new set of > macros that behave like the version you propose here but leave > the old macros in place until the last such #ifdef has been removed. > > Arnd Agh, you are right. We cannot change all the callsites atomically due to the huge amount of users. -- Best Regards Masahiro Yamada
