Re: [PATCH] usb-musb: keep VBUS on when device is disconnected

Tony Lindgren
2017-05-12T17:46:27Z

* Bin Liu <b-liu@ti.com> [170512 10:43]:
> On Fri, May 12, 2017 at 10:21:35AM -0700, Tony Lindgren wrote:
> > * Bin Liu <b-liu@ti.com> [170512 08:24]:
> > > On Fri, May 12, 2017 at 07:58:49AM -0700, Tony Lindgren wrote:
> > > > OK. No better ideas except I think we should probably have a separate
> > > > timer for keeping VBUS on after state changes eventually.
> > >
> > > Currently with the patch below, VBUS is constantly on for host-only
> > > mode, and this is what we want. Why we need a separate timer? No one
> > > cuts VBUs now for host-only mode.
> >
> > Oh I was just thinking what we might want to do in the future if
> > we want to cut off VBUS when no devices are connected. If we have
>
> Okay, I see. But I don't think we will ever want to turn off VBUS when
> no devices attached for host-only mode. Any other controllers do this?
>
> Turning off VBUS doesn't save us much, because it comes from an external
> power rail, and no one consumes it when no devices are attached.
>
> I believe keeping the controller idle as what we have now is sufficient.

OK fine with me.

Regards,

Tony