Re: [PATCH v2 1/6] PM: core: Remove DEFINE_UNIVERSAL_DEV_PM_OPS() macro

[Paul Cercueil]

Hi Ulf,

Le ven., janv. 7 2022 at 17:26:07 +0100, Ulf Hansson 
<ulf.hansson@xxxxxxxxxx> a écrit :
> On Wed, 5 Jan 2022 at 19:29, Paul Cercueil <paul@xxxxxxxxxxxxxxx> 
> wrote:
> >  The deprecated UNIVERSAL_DEV_PM_OPS() macro uses the provided 
> > callbacks
> >  for both runtime PM and system sleep, which is very likely to be a
> >  mistake, as a system sleep can be triggered while a given device is
> >  already PM-suspended, which would cause the suspend callback to be
> >  called twice.
> >
> >  The amount of users of UNIVERSAL_DEV_PM_OPS() is also tiny (16
> >  occurences) compared to the number of places where
> >  SET_SYSTEM_SLEEP_PM_OPS() is used with pm_runtime_force_suspend() 
> > and
> >  pm_runtime_force_resume(), which makes me think that none of these 
> > cases
> >  are actually valid.
> >
> >  As this macro is currently unused, remove it before someone starts 
> > to
> >  use it in yet another invalid case.
>
> I assume you refer to DEFINE_UNIVERSAL_DEV_PM_OPS here. Can you
> perhaps make that more clear?

I can.

> >  Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
> >  Acked-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> >  ---
> >
> >  Notes:
> >      v2: No change
> >
> >   include/linux/pm.h | 19 ++++++-------------
> >   1 file changed, 6 insertions(+), 13 deletions(-)
> >
> >  diff --git a/include/linux/pm.h b/include/linux/pm.h
> >  index e1e9402180b9..31bbaafb06d2 100644
> >  --- a/include/linux/pm.h
> >  +++ b/include/linux/pm.h
> >  @@ -366,6 +366,12 @@ static const struct dev_pm_ops name = { \
> >          SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
> >   }
> >
> >  +/* Deprecated. Use DEFINE_SIMPLE_DEV_PM_OPS() instead. */
> >  +#define SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
> >  +const struct dev_pm_ops __maybe_unused name = { \
> >  +       SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
> >  +}
> >  +
> >   /*
> >    * Use this for defining a set of PM operations to be used in all 
> > situations
> >    * (system suspend, hibernation or runtime PM).
> >  @@ -379,19 +385,6 @@ static const struct dev_pm_ops name = { \
> >    * .resume_early(), to the same routines as .runtime_suspend() and
> >    * .runtime_resume(), respectively (and analogously for 
> > hibernation).
> >    */
> >  -#define DEFINE_UNIVERSAL_DEV_PM_OPS(name, suspend_fn, resume_fn, 
> > idle_fn) \
> >  -static const struct dev_pm_ops name = { \
> >  -       SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
> >  -       RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
> >  -}
> >  -
> >  -/* Deprecated. Use DEFINE_SIMPLE_DEV_PM_OPS() instead. */
> >  -#define SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
> >  -const struct dev_pm_ops __maybe_unused name = { \
> >  -       SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
> >  -}
> >  -
> >  -/* Deprecated. Use DEFINE_UNIVERSAL_DEV_PM_OPS() instead. */
>
> Shouldn't this macro be deprecated any more?

I can only deprecate it if there is an alternative for it. The 
alternative is DEFINE_RUNTIME_DEV_PM_OPS() which is added in patch 4/6.

Cheers,
-Paul

> >   #define UNIVERSAL_DEV_PM_OPS(name, suspend_fn, resume_fn, idle_fn) 
> > \
> >   const struct dev_pm_ops __maybe_unused name = { \
> >          SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
> >  --
> >  2.34.1
>
> Kind regards
> Uffe