Re: [RFC/PATCH 1/5] usb: otg: add notifier support

From: David Brownell
Date: Tue Jan 26 2010 - 10:21:36 EST


On Tuesday 26 January 2010, Felipe Balbi wrote:
> >
> >Thing is, supplying current is a bit more involved.  If the
> >board can't supply 300 mA, the USB configuration selection
> >mechanism has to know that, so it never selects peripheral
> >configurations which require that much current.
>
> but that's done already by the usb core, no ? It rules out configuration
> based on the hub->power_budget (can't remember if the field is that
> exact name).

Yes, it handles that ... but where does the power budget
come from? That's what I meant by "more involved".

As in, the host/supplying side of the power equation can't
be event driven like the peripheral/consuming side can.

And that's another reason I think it's best to fully solve
the common (peripheral, recharge-that-batter) case first.

- Dave
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