RE: [PATCH v2 2/3] usb: chipidea: imx: support disabling runtime-pm

Peter Chen
2020-07-20T03:44:40Z

> On Wed, 2020-07-15 at 00:51 +0000, Peter Chen wrote:
> >
> > > The Toradex Colibri iMX6ULL board has a special USB hardware design.
> > > With runtime-pm enabled USB reset itself continuously. Furthermore
> > > the OTG port is also not enumerating devices if the Chipidea IP is
> > > in runtime sleep mode and a device or host gets plugged in.
> > >
> >
> > Hi Philippe,
> >
> > You may describe the detail what's the special USB hardware design for
> > your board,
>
> If I only knew the root-cause of that problem - unfortunately I don't.
> That's also why I have such a hard time to describe it.
>
> > and why it causes the problem, and why disable runtime pm could fix
> > this issue, then,
>
> I cannot provide the 'why' part yet. I'll try something more and hope I can provide
> you guys with the exact description.
>
> > the other users could know if it could apply to their platforms or not
> > in future.
>
> I only found out about it because you were pointing me in that direction. I debugged
> for hours now and didn't came to the root-cause of the issue. I think to really
> understand it I would need to know much more about the Chipidea IP.
>
> I'll get back to you guys with a proposal for a new description.
>

Philippe, is it possible to share your USB hardware design at 6ULL?
And how ci_hdrc_gadget_connect is called when the runtime pm is disabled?

Thanks,
Peter