[PATCH 08/21] usb: chipidea: Kick OTG state machine for AVVIS with vbus extcon

[Stephen Boyd]

Quoting Peter Chen (2016-06-28 20:09:13)
> On Sun, Jun 26, 2016 at 12:28:25AM -0700, Stephen Boyd wrote:
> > Force the OTG state machine to go forward when we're using an
> > extcon for vbus detection. In this case, the controller may never
> > raise an interrupt for AVVIS, so we need to simulate the event by
> > toggling the appropriate OTG fsm bits and kicking the state
> > machine again.
> > 
> 
> Well, I think you may misunderstand the OTG FSM and dual-role.
> From my and Felipe's point, there are seldom users for USB FSM,
> there are only OTG FSM spec and related OTG certification.

Probably yes.

> 
> The OTG FSM needs related SoC support, the vbus will be off at
> several states, and the SRP should be supported by SoC.
> 
> By default, the dts needs below properties for disabling it if you
> choose otg fsm support at kernel configuration.
> 
> &usbotg1 {
>         vbus-supply = <&reg_usb_otg1_vbus>;
>         srp-disable;
>         hnp-disable;
>         adp-disable;
>         status = "okay";
> };
> 
> See Documentation/devicetree/bindings/usb/generic.txt.

Does this mean we should be setting all those properties if we're using
an extcon for vbus and id? I have noticed that vbus is powered off after
some time when no device is connected and we're in A_HOST state because
the timeout for a B device connection happens.