Re: [PATCH v5 1/4] usb: dbc: early driver for xhci debug capability

From: Ingo Molnar
Date: Thu Jan 26 2017 - 03:17:45 EST

* Lu Baolu <> wrote:

> Hi Ingo,
> On 01/26/2017 03:19 PM, Ingo Molnar wrote:
> > * Lu Baolu <> wrote:
> >
> >> Fair enough.
> >>
> >> USB connection is stable enough, unless the user unplugs the
> >> USB cable during debugging.
> > What does the hardware do in this case? The XHCI registers are in the host
> > hardware, so they won't disappear, right? Is there some cable connection status
> > bit we can extract without interrupts?
> Yes, there are register bits for us to know the cable status. I will go
> through the spec again and give you more accurate answer later.

Ok, that's good news - so we don't really have to time out and we don't have to
rely on the user holding the phone right either.

> I'm sorry. I will be off during the next 7 days for Chinese New Year
> holiday. My email access will be very limited during this time. I will
> revisit this thread after I am back from holiday.
> Sorry for the inconvenience.

No problem, have fun!