Messages in this thread | | | From | Kevin Hilman <> | Subject | Re: [RFC][PATCH] Power domains for platform bus type | Date | Mon, 31 Jan 2011 15:43:41 -0800 |
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"Rafael J. Wysocki" <rjw@sisk.pl> writes:
>> Also, what is the use case for having 2 sets of power_domain ops? My >> gut tells me that you'd only want to do post ops on the >> {freeze,suspend,poweroff} path and pre ops on the {resume,thaw,restore} >> path. It seems overly engineered to me, but I may be missing >> something fundamental. > > Well, that's a part of the RFC, actually. :-) > > For the subsystems I've worked with (PCI, ACPI, PNP to some extent) one set > would be sufficient, but I don't know of every possible use case.
For the on-chip SoC devices we're managing with OMAP, we're currently only using one set: post ops on [runtime_]suspend and pre ops on [runtime_]resume.
However, I could imagine (at least conceptually) using the pre ops on suspend to do some constraints checking and/or possibly some management/notification of dependent devices. Another possiblity (although possibly racy) would be using the pre ops on suspend to initiate some high-latency operations.
I guess the main problem with two sets is wasted space. e.g, if I move OMAP to this (already hacking on it) there will be only 2 functions used in post ops: [runtime_]suspend() and 2 used in pre ops [runtime_]_resume().
Kevin
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