[PATCH] PM / Domains: Change prototype for the ->attach_dev() callback

[Ulf Hansson]

On 6 November 2014 00:11, Kevin Hilman <khilman at kernel.org> wrote:
> "Rafael J. Wysocki" <rjw at rjwysocki.net> writes:
>
>> On Wednesday, November 05, 2014 02:43:31 PM Kevin Hilman wrote:
>>> Dmitry Torokhov <dmitry.torokhov at gmail.com> writes:
>>>
>>> > On Thu, Oct 30, 2014 at 01:38:30PM -0700, Kevin Hilman wrote:
>>> >> "Rafael J. Wysocki" <rjw at rjwysocki.net> writes:
>>> >>
>>> >> > On Thursday, October 30, 2014 01:02:49 PM Ulf Hansson wrote:
>>> >> >> Convert the prototype to return and int. This is just an initial step,
>>> >> >> needed to support error handling.
>>> >> >>
>>> >> >> Signed-off-by: Ulf Hansson <ulf.hansson at linaro.org>
>>> >>
>>> >> Acked-by: Kevin Hilman <khilman at linaro.org>
>>> >>
>>> >> >>
>>> >> >> This patch is intended as fix for 3.18 rc[n]. Why?
>>> >> >>
>>> >> >> There are other SOC specific patches around that adds genpd support and which
>>> >> >> implements the ->attach_dev() callback. To prevent having an "atomic" patch
>>> >> >> during the next release cycle, let's change the prototype now instead.
>>> >> >>
>>> >> >> Further patches will add the actual error handling in genpd and these can then
>>> >> >> be reviewed and tested thoroughly.
>>> >> >
>>> >> > So we have no users of ->attach_dev at the moment, right?
>>> >>
>>> >> Not in mainline, but there are a couple getting ready to hit -next, so
>>> >> we wanted to fix this before they arrive so that adding the error
>>> >> handling will be easier.
>>> >
>>> > BTW, while we are at it, can we also pass the domain itself to
>>> > attach_dev() and detach_dev()? If anything it helps with debugging (you
>>> > can print domain name from the callbacks).
>>>
>>> Agreed, and it makes it match the other callbacks (power_off, power_on)
>>> which currently take struct generic_pm_domain *domain.
>>>
>>> Updated version of $SUBJECT patch below.
>>
>> The subject and changelog need to be updated too IMO.
>>
>
> Right.  Here you go.
>
> Kevin

Thanks for helping out Kevin!

Kind regards
Uffe

>
>
> ----- >8 ------
> From c18a6bf3121979c4102ba4f7edb3ac41e3921fc6 Mon Sep 17 00:00:00 2001
> From: Ulf Hansson <ulf.hansson at linaro.org>
> Date: Thu, 30 Oct 2014 13:02:49 +0100
> Subject: [PATCH] PM / Domains: Change prototype for the attach and detach
>  callbacks
>
> Convert the prototypes to return an int in order to support error
> handling in these callbacks.
>
> Also, as suggested by Dmitry Torokhov, pass the domain pointer for use
> inside the callbacks, and so that they match the existing
> power_on/power_off callbacks which currently take the domain pointer.
>
> Acked-by: Dmitry Torokhov <dmitry.torokhov at gmail.com>
> [khilman: added domain as parameter to callbacks, as suggested by Dmitry]
> Signed-off-by: Ulf Hansson <ulf.hansson at linaro.org>
> Signed-off-by: Kevin Hilman <khilman at linaro.org>
> ---
>  drivers/base/power/domain.c | 4 ++--
>  include/linux/pm_domain.h   | 6 ++++--
>  2 files changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> index 40bc2f4072cc..b520687046d4 100644
> --- a/drivers/base/power/domain.c
> +++ b/drivers/base/power/domain.c
> @@ -1437,7 +1437,7 @@ int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
>         spin_unlock_irq(&dev->power.lock);
>
>         if (genpd->attach_dev)
> -               genpd->attach_dev(dev);
> +               genpd->attach_dev(genpd, dev);
>
>         mutex_lock(&gpd_data->lock);
>         gpd_data->base.dev = dev;
> @@ -1499,7 +1499,7 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd,
>         genpd->max_off_time_changed = true;
>
>         if (genpd->detach_dev)
> -               genpd->detach_dev(dev);
> +               genpd->detach_dev(genpd, dev);
>
>         spin_lock_irq(&dev->power.lock);
>
> diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
> index 73e938b7e937..b3ed7766a291 100644
> --- a/include/linux/pm_domain.h
> +++ b/include/linux/pm_domain.h
> @@ -72,8 +72,10 @@ struct generic_pm_domain {
>         bool max_off_time_changed;
>         bool cached_power_down_ok;
>         struct gpd_cpuidle_data *cpuidle_data;
> -       void (*attach_dev)(struct device *dev);
> -       void (*detach_dev)(struct device *dev);
> +       int (*attach_dev)(struct generic_pm_domain *domain,
> +                         struct device *dev);
> +       void (*detach_dev)(struct generic_pm_domain *domain,
> +                          struct device *dev);
>  };
>
>  static inline struct generic_pm_domain *pd_to_genpd(struct dev_pm_domain *pd)
> --
> 2.1.0
>