Re: [RFC][PATCH] Power domains for platform bus type

"Rafael J. Wysocki" [off-list ref] writes:

Hi,

This is something we discussed during the last Linux Plumbers Conference.

The problem appears to be that the same device may be used in different
systems in different configurations such that actions necessary for the
device's power management can vary from one system to another.  In those
cases the drivers' power management callbacks are generally not sufficient,
because they can't take the configuration of the whole system into account.

I think this issue may be addressed by adding objects that will represent
power domains and will provide power management callbacks to be executed
in addition to the device driver's PM callbacks, which is done by the patch
below.

Please have a look at it and tell me what you think.

FYI... I just tested this patch on OMAP by converting our existing use
of platform_bus_set_ops() to use this approach by adding a powerdomain
to each omap_device.   

Note we're currently only overriding the runtime_[suspend|resume]
methods, so those are the only paths I've tested.

Kevin