Messages in this thread |  | | Date | Tue, 23 Jun 2009 13:02:15 -0400 (EDT) | From | Alan Stern <> | Subject | Re: [patch update 3] PM: Introduce core framework for run-time PM of I/O devices |
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On Mon, 22 Jun 2009, Rafael J. Wysocki wrote:
> > And of course, synchronous pm_runtime_resume should always increment the > > counter. > > Sure.
Now that I've thought about it some more, I decided that we might want to be more flexible. Without subjecting you to the entire line of reasoning, let's just say that I'm starting to wonder whether it's such a good idea to tie the counter increments to the PM core runtime resume calls at all.
Maybe it would be better (easier to use, less constraining) to require the runtime_resume callback to do its own pm_runtime_get. That way the driver would be entirely responsible for managing the usage counter; the PM core wouldn't be involved. pm_runtime_get would simply increment the counter, so it could be used even in interrupt context. At the moment, I don't see any need for it to queue an autoresume request if the device happens to be suspended.
Something like this was probably your intention all along. :-)
Alan Stern
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