Re: [PATCH V2 0/4] introduce device async actions mechanism

From: Alan Stern
Date: Wed Aug 12 2009 - 10:03:30 EST


On Wed, 12 Aug 2009, Rafael J. Wysocki wrote:

> That looks quite complicated at first sight, but asynchronous resume with
> completions can be done in a relatively simple patch. I've got one, so
> tomorow I'll post it for further discussion.

Okay. I would think that managing the threads would account for most
of the complexity in either implementation, but I'll wait to see how
your approach works out.

> Thanks,
> Rafael
>
>
> PS
> Did you have a chance to look at rev. 15 of the runtime PM patch
> (http://patchwork.kernel.org/patch/40306/)?

Yes, sorry for not getting back to you. It looks okay.

The one thing I'm not sure of is the pm_runtime_put_noidle calls in
driver_probe_device and __device_release_driver. It seems that we
should always call pm_runtime_put regardless of whether the probe
succeeds or not.

For example, the USB stack is set up to suspend devices that don't have
a driver (this is handled at the bus subsystem level). But if probing
failed, there wouldn't be any idle callback and so the suspend wouldn't
take place.

Alan Stern

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