Re: Non-enumerable devices on USB and other enumerable buses

[Alan Stern]

On Wed, 14 Aug 2013, Mark Brown wrote:

> On Mon, Aug 12, 2013 at 09:04:00PM -0400, Alan Stern wrote:
> 
> > The bus code would need hooks installed wherever the platform wants to 
> > do something extra.  This could end up growing to a lot of hooks.  How 
> > can the whole thing be done in a reasonable fashion?
> 
> I'd expect that we're just looking at hooks around connection and
> disconnection here here - if we're looking at much more it seems like we
> must be doing something wrong.

Connection and disconnection of what?

In the example mentioned earlier, the GPIOs to power an on-board USB
hub would have to be initialized when the host controller was started.  
You wouldn't want to wait for the on-board hub to be detected, because
without those GPIOs set properly, it never would be discovered on the
USB bus.  Right?

Perhaps the platform-level code would need to hook into the places
where the discoverable bus is registered and unregistered.

Alan Stern

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