Re: [PATCH v8 3/4] PM / sleep: Go direct_complete if driver has no callbacks

From: Ulf Hansson
Date: Fri Oct 02 2015 - 04:40:57 EST


On 2 October 2015 at 10:10, Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx> wrote:
> On 2 October 2015 at 09:48, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote:
>> On 2 October 2015 at 09:14, Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx> wrote:
>>> If a suitable prepare callback cannot be found for a given device and
>>> its driver has no PM callbacks at all, assume that it can go direct to
>>> complete when the system goes to sleep.
>>>
>>> The reason for this is that there's lots of devices in a system that do
>>> no PM at all and there's no reason for them to prevent their ancestors
>>> to do direct_complete if they can support it.
>>>
>>> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx>
>>> ---
>>>
>>> Changes in v8:
>>> - Move no_pm_callbacks field into CONFIG_PM_SLEEP
>>> - Call device_check_pm_callbacks only after a device is bound or unbound
>>
>> Devices that don't use a driver, will not get this feature for "free".
>> I expect in those cases, they will have to call
>> device_check_pm_callbacks() themselves, right?
>
> You are right, but wonder if we shouldn't go back to calling
> device_check_pm_callbacks() from device_pm_add() and
> dev_pm_domain_set() so they don't have to.

That seems reasonable to me, and I didn't quite understand why you
decided to remove it. :-)

Kind regards
Uffe

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