Messages in this thread | | | From | Coiby Xu <> | Date | Fri, 30 Oct 2020 22:22:42 +0800 | Subject | Re: [PATCH 3/9] mfd: intel_soc_pmic: remove unnecessary CONFIG_PM_SLEEP |
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On Thu, Oct 29, 2020 at 07:04:44PM +0200, Andy Shevchenko wrote: >On Thu, Oct 29, 2020 at 5:27 PM Lee Jones <lee.jones@linaro.org> wrote: >> On Thu, 29 Oct 2020, Coiby Xu wrote: >> > On Thu, Oct 29, 2020 at 01:00:29PM +0200, Andy Shevchenko wrote: >> > > On Thu, Oct 29, 2020 at 06:06:41PM +0800, Coiby Xu wrote: >> > > > SIMPLE_DEV_PM_OPS has already took good care of CONFIG_PM_CONFIG. >> > > >> > > Have you compiled this with >> > > % make W=1 ... >> > > ? >> > > >> > >> > Sorry my bad. I thought I had run "make modules" with CONFIG_PM_SLEEP >> > disabled. I'll run "make W=1 M=..." for each driver after adding >> > __maybe_unused in v2. >> >> No, thank you. Just keep it as it is. >> >> The current code is space saving. > >Perhaps you need to go thru __maybe_unused handling. >There are pros and cons of each approach, but not above. > Can you elaborate on the pros and cons of each approach? There's convincing reason to prefer __maybe_unused over CONFIG_PM_SLEEP according to Arnd Bergmann [1],
> > By and large, drivers handle this by using a CONFIG_PM_SLEEP ifdef. > > > > Unless you can make an extremely convincing argument why not to do > > so here, I'd like you to handle it that way instead. > > [adding linux-pm to Cc] > > The main reason is that everyone gets the #ifdef wrong, I run into > half a dozen new build regressions with linux-next every week on > average, the typical problems being: > > - testing CONFIG_PM_SLEEP instead of CONFIG_PM, leading to an unused > function warning > - testing CONFIG_PM instead of CONFIG_PM_SLEEP, leading to a build > failure > - calling a function outside of the #ifdef only from inside an > otherwise correct #ifdef, again leading to an unused function > warning > - causing a warning inside of the #ifdef but only testing if that > is disabled, leading to a problem if the macro is set (this is > rare these days for CONFIG_PM as that is normally enabled) > > Using __maybe_unused avoids all of the above.
You option is valuable to me because I'm making a tree-wide change.
Currently there are 929 drivers having device PM callbacks,
$ grep -rI "\.pm = &" --include=*.c ./|wc -l 929
I put all files having device PM callbacks into four categories based on weather a file has CONFIG_PM_SLEEP or PM macro like SET_SYSTEM_SLEEP_PM_OPS, here are the statistics, 1. have both CONFIG_PM_SLEEP and PM_OPS macro: 213 2. have CONFIG_PM_SLEEP but no PM_OPS macro: 19 3. have PM macro but not CONFIG_PM_SLEEP: 347 4. no PM macro or CONFIG_PM_SLEEP: 302
[1] https://lore.kernel.org/patchwork/comment/919944/
>-- >With Best Regards, >Andy Shevchenko
-- Best regards, Coiby
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