Re: [RFC][PATCH] PM / Platform: Remove __weak definitions of runtime PM callbacks

[Kevin Hilman]

Hi Rafael, Magnus,

"Rafael J. Wysocki" <rjw@xxxxxxx> writes:

> From: Rafael J. Wysocki <rjw@xxxxxxx>
>
> Remove the __weak definitions of platform bus type runtime PM
> callbacks, make platform_dev_pm_ops point to the generic routines
> as appropriate and allow architectures using platform_dev_pm_ops to
> replace the runtime PM callbacks in that structure with their own
> set.
>
> Convert architectures providing its own definitions of the platform
> runtime PM callbacks to use the new mechanism.
>
> Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>

I dont't think we should be adding yet another new interface for setting
platform-specific runtime PM ops.

We now have 3.  Two existing ones:

1) new device power domains (presumably preferred)
2) platform_bus_set_pm_ops() (disliked by many)

and now the new one you create here

3) platform_set_runtime_pm_ops()

This new one is basically the same as platform_bus_set_pm_ops(), but
targetted only at runtime PM ops, and also has all the same problems
that have been discussed before.  Namely, it overrides the pm ops for
*every* device on the platform_bus, instead of targetting only specific
devices.  With the new device power domains, we can target specific
devices.

Wouldn't the right way to go here be to convert mach-shmobile over to
using device power domains?

The patch below against v2.6.39-rc2 combined with your patch (minus the
mach-shmobile/* changes) should do it.

Magnus, care to test?

If SH-mobile is converted to use device powerdomains, not only can we
drop this new platform_set_runtime_pm_ops(), but we can also drop
platform_bus_set_pm_ops() (I have a patch for this as soon as I post
the OMAP conversions to device power domains.)

That will leave only a single interface for overriding the runtime PM
ops: device power domains.  Personally, I prefer that as it's flexible
enough, and also allows platforms to target only specific devices
instead of the whole bus.

Kevin