Re: [PATCH v2] drivers: base: add support to skip power management in device/driver model

From: Sudeep Holla
Date: Thu Feb 14 2019 - 07:05:23 EST


On Thu, Feb 14, 2019 at 11:16:09AM +0000, Sudeep Holla wrote:
> On Wed, Feb 13, 2019 at 11:17:47PM +0100, Rafael J. Wysocki wrote:
> > On Wed, Feb 13, 2019 at 1:01 PM Sudeep Holla <sudeep.holla@xxxxxxx> wrote:

[...]

> > > diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
> > > index 0992e67e862b..2a29c3d4e240 100644
> > > --- a/drivers/base/power/main.c
> > > +++ b/drivers/base/power/main.c
> > > @@ -124,6 +124,10 @@ void device_pm_unlock(void)
> > > */
> > > void device_pm_add(struct device *dev)
> > > {
> > > + /* No need to create pm sysfs if explicitly specified as not required */
> >
> > Is this really about sysfs?
> >
>
> Nope, copy-paste from dpm_sysfs_add, will drop it.
>
> > > + if (device_pm_not_required(dev))
> >
> > Should power.disable_depth be bumped up here or while setting the "no PM" flag?
> >
>
> OK, I missed that.
>

Looking at it,
1. We can't set it when we set "no PM" flag as pm_runtime_init called later
initialise it to 1
2. We can bump it here, but I see it's usage self contained in runtime.c
and may look odd to access it here.

More basic question is should we really need to bump it to 2 as its
initialised to 1 in runtime_init.

--
Regards,
Sudeep