Re: [PATCH] pwm: Rename pwm_get_state() to better reflect its semantic

From: Thierry Reding
Date: Fri Apr 09 2021 - 08:08:48 EST


On Tue, Apr 06, 2021 at 03:43:56PM +0200, Uwe Kleine-König wrote:
> Hello Thierry,
>
> On Tue, Apr 06, 2021 at 01:16:31PM +0200, Thierry Reding wrote:
> > On Tue, Apr 06, 2021 at 09:30:36AM +0200, Uwe Kleine-König wrote:
> > > Given that lowlevel drivers usually cannot implement exactly what a
> > > consumer requests with pwm_apply_state() there is some rounding involved.
> > >
> > > pwm_get_state() traditionally returned the setting that was requested most
> > > recently by the consumer (opposed to what was actually implemented in
> > > hardware in reply to the last request). To make this semantic obvious
> > > rename the function.
> > >
> > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
> > > ---
> > > Documentation/driver-api/pwm.rst | 6 +++-
> > > drivers/clk/clk-pwm.c | 2 +-
> > > drivers/gpu/drm/i915/display/intel_panel.c | 4 +--
> > > drivers/input/misc/da7280.c | 2 +-
> > > drivers/input/misc/pwm-beeper.c | 2 +-
> > > drivers/input/misc/pwm-vibra.c | 4 +--
> > > drivers/pwm/core.c | 4 +--
> > > drivers/pwm/pwm-atmel-hlcdc.c | 2 +-
> > > drivers/pwm/pwm-atmel.c | 2 +-
> > > drivers/pwm/pwm-imx27.c | 2 +-
> > > drivers/pwm/pwm-rockchip.c | 2 +-
> > > drivers/pwm/pwm-stm32-lp.c | 4 +--
> > > drivers/pwm/pwm-sun4i.c | 2 +-
> > > drivers/pwm/sysfs.c | 18 ++++++------
> > > drivers/regulator/pwm-regulator.c | 4 +--
> > > drivers/video/backlight/pwm_bl.c | 10 +++----
> > > include/linux/pwm.h | 34 ++++++++++++++--------
> > > 17 files changed, 59 insertions(+), 45 deletions(-)
> >
> > Honestly, I don't think this is worth the churn. If you think people
> > will easily get confused by this then a better solution might be to more
> > explicitly document the pwm_get_state() function to say exactly what it
> > returns.
>
> I'm not so optimistic that people become aware of the semantic just
> because there is documentation describing it and I strongly believe that
> a good name for functions is more important than accurate documentation.
>
> If you don't agree, what do you think about the updated wording in
> Documentation/driver-api/pwm.rst?

Yeah, that clarifies this a bit. I can apply that hunk of the patch
separately.

> > But there's no need to make life difficult for everyone by
> > renaming this to something as cumbersome as this.
>
> I don't expect any merge conflicts (and if still a problem occurs
> resolving should be trivial enough). So I obviously don't agree to your
> weighing.

I wasn't talking about merge conflicts but instead about the extra churn
of changing all consumers and having to type all these extra characters
for no benefit.

Thierry

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