On Wed, 2 Apr 2008, Oliver Neukum wrote:

quoted text
> Am Mittwoch, 2. April 2008 17:13:11 schrieb Alan Stern:
> > Basically yes.  Subsystems and drivers are allowed to keep devices
> > suspended if they were suspended before the system went to sleep.  
> > Remember, the purpose of the resume method is to let drivers know that
> > the system is now awake, not to force them to put their devices into a
> > high-power state.
> 
> Well, sometimes it is exactly that what we desire, eg. as a side effect
> of lsusb. Should the callbacks have different semantics depending on
> the reason you call them? And how should that information be transferred?

Which callbacks are you referring to?  When lsusb opens a device and
does an autoresume, it does not call the same routine as the PM core
does when resuming from a system sleep.  lsusb ends up calling
usb_autoresume_device() whereas the PM core ends up calling
usb_resume(), which is the function you quoted earlier.

Alan Stern

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