[PATCH] PM / Domains: Try power off masters in error path of __pm_genpd_poweron()

[Krzysztof Kozlowski]

2015-06-25 20:17 GMT+09:00 Ulf Hansson <ulf.hansson at linaro.org>:
> On 11 June 2015 at 14:33, Krzysztof Kozlowski <k.kozlowski.k at gmail.com> wrote:
>> W dniu 11.06.2015 o 20:51, Ulf Hansson pisze:
>>> While powering up a genpd, its domain masters are first being powered up.
>>> In the error path of __pm_genpd_poweron(), we didn't care to try power off
>>> these domain masters. Let's deal with that to avoid leaving unused PM
>>> domains powered.
>>>
>>> Signed-off-by: Ulf Hansson <ulf.hansson at linaro.org>
>>> ---
>>>  drivers/base/power/domain.c | 30 +++++++++++++++++-------------
>>>  1 file changed, 17 insertions(+), 13 deletions(-)
>>>
>>> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
>>> index 2327613..32dcb80 100644
>>> --- a/drivers/base/power/domain.c
>>> +++ b/drivers/base/power/domain.c
>>> @@ -235,6 +235,18 @@ static int genpd_power_off(struct generic_pm_domain *genpd)
>>>  }
>>>
>>>  /**
>>> + * genpd_queue_power_off_work - Queue up the execution of pm_genpd_poweroff().
>>> + * @genpd: PM domait to power off.
>>> + *
>>> + * Queue up the execution of pm_genpd_poweroff() unless it's already been done
>>> + * before.
>>> + */
>>> +static void genpd_queue_power_off_work(struct generic_pm_domain *genpd)
>>> +{
>>> +     queue_work(pm_wq, &genpd->power_off_work);
>>> +}
>>> +
>>> +/**
>>>   * __pm_genpd_poweron - Restore power to a given PM domain and its masters.
>>>   * @genpd: PM domain to power up.
>>>   *
>>> @@ -315,8 +327,12 @@ static int __pm_genpd_poweron(struct generic_pm_domain *genpd)
>>>       return 0;
>>>
>>>   err:
>>> -     list_for_each_entry_continue_reverse(link, &genpd->slave_links, slave_node)
>>> +     list_for_each_entry_continue_reverse(link,
>>> +                                     &genpd->slave_links,
>>> +                                     slave_node) {
>>>               genpd_sd_counter_dec(link->master);
>>> +             genpd_queue_power_off_work(link->master);
>>
>> It looks sensible to revert work already done however I wonder if this
>> is necessary for each slave. The first successful call to
>> pm_genpd_poweroff() will also walk through slave_links and queue the work.
>>
>
> For the current genpd, each slave link represents that the current
> genpd is a subdomain to another genpd. The corresponding master for
> each link is the "link->master". As genpds are allowed to have several
> masters, we can't just try to power off one of them.

Right, makes sense.

Reviewed-by: Krzysztof Kozlowski <k.kozlowski at samsung.com>

Best regards,
Krzysztof