Re: [PATCH v6 7/8, needs improvement] hid: add suspend/resume hooks for hid drivers

Bruno Prémont
2010-04-12T16:56:18Z

On Mon, 12 April 2010 Jiri Kosina <jkosina@suse.cz> wrote:
> On Sun, 11 Apr 2010, Bruno Prémont wrote:
>
> > > > As far as I understand the code, in auto-suspend case if the driver
> > > > sends commands to the device it will have to call usbhid_wait_io().
> > > > Please correct me if I'm wrong!
> > >
> > > It's not needed. There is a queuing mechanism in place on
> > > 'resumption_waker' workqueue.
> >
> > So the driver is not allowed to ask the device to do something
> > at auto-suspend time (as that would abort the auto-suspension).
>
> What do you mean by "is not allowed" exactly?
>
> Yes, it will wake the device up from auto-suspension. However, that's
> usually what you want to happen, is there is anything you need to dispatch
> to the device, isn't it?

I thought of a report to send to device to ask the device to disable some
power using feature (e.g. turning off or dimming LEDs)

> What exactly is the situation you are trying to handle?

That's rather a generic question, not related to any implementation.

Maybe I'm mixing suspend and USB-autosuspend too much?

Thanks,
Bruno