Re: [PATCH v5 17/20] ACPI: platform_profile: Check all profile handler to calculate next

[Mario Limonciello <mario.limonciello@xxxxxxx>]

On 11/7/2024 02:58, Armin Wolf wrote:
> Am 07.11.24 um 07:02 schrieb Mario Limonciello:
>
> > As multiple platform profile handlers might not all support the same
> > profile, cycling to the next profile could have a different result
> > depending on what handler are registered.
> >
> > Check what is active and supported by all handlers to decide what
> > to do.
> >
> > Tested-by: Mark Pearson <mpearson-lenovo@xxxxxxxxx>
> > Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> > ---
> > v5:
> >   * Adjust mutex use
> > ---
> >   drivers/acpi/platform_profile.c | 23 ++++++++++++++---------
> >   1 file changed, 14 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/ 
> > platform_profile.c
> > index 7f302ac4d3779..2c466f2d16b42 100644
> > --- a/drivers/acpi/platform_profile.c
> > +++ b/drivers/acpi/platform_profile.c
> > @@ -411,34 +411,39 @@ EXPORT_SYMBOL_GPL(platform_profile_notify);
> >
> >   int platform_profile_cycle(void)
> >   {
> > +    enum platform_profile_option next = PLATFORM_PROFILE_LAST;
> >       enum platform_profile_option profile;
> > -    enum platform_profile_option next;
> > +    unsigned long choices;
> >       int err;
> >
> >       if (!class_is_registered(&platform_profile_class))
> >           return -ENODEV;
> >
> >       scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &profile_lock) {
> > -        if (!cur_profile)
> > -            return -ENODEV;
> > +        err = class_for_each_device(&platform_profile_class, NULL,
> > +                        &profile, _aggregate_profiles);
> > +        if (err)
> > +            return err;
> >
> > -        err = cur_profile->profile_get(cur_profile, &profile);
> > +        err = class_for_each_device(&platform_profile_class, NULL,
> > +                        &choices, _aggregate_choices);
> >           if (err)
> >               return err;
> >
> > -        next = find_next_bit_wrap(cur_profile->choices, 
> > PLATFORM_PROFILE_LAST,
> > +        next = find_next_bit_wrap(&choices,
> > +                      PLATFORM_PROFILE_LAST,
> >                         profile + 1);
>
> Could it be that this would lead to be "custom" profile being selected 
> under some conditions?

Yeah, you're right.  If all drivers supported custom then this could 
happen.  I'll clear custom like this:

		choices &= ~BIT(PLATFORM_PROFILE_CUSTOM);

> Also _aggregate_profiles() expects profile to be initialized with 
> PLATFORM_PROFILE_LAST.

Will correct initialization in platform_profile_cycle() to this.

	enum platform_profile_option profile = PLATFORM_PROFILE_LAST;

But this also raises a good point.  If _aggregate_profiles() returns
custom then this should be an error because next profile is undefined.
So I'll catch that like this.
		err = class_for_each_device()
		if (err)
			return err;
		if (profile == PLATFORM_PROFILE_CUSTOM)
			return -EINVAL;
> Thanks,
> Armin Wolf
>
> > -        if (WARN_ON(next == PLATFORM_PROFILE_LAST))
> > -            return -EINVAL;
> > +        err = class_for_each_device(&platform_profile_class, NULL, 
> > &next,
> > +                        _store_class_profile);
> >
> > -        err = cur_profile->profile_set(cur_profile, next);
> >           if (err)
> >               return err;
> >       }
> >
> >       sysfs_notify(acpi_kobj, NULL, "platform_profile");
> > -    return 0;
> > +
> > +    return err;
> >   }
> >   EXPORT_SYMBOL_GPL(platform_profile_cycle);