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Date: Thu, 26 Jan 2017 09:17:33 +0100
From: Ingo Molnar <mingo@kernel.org>
To: Lu Baolu <baolu.lu@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Mathias Nyman <mathias.nyman@linux.intel.com>,
        Ingo Molnar <mingo@redhat.com>, tglx@linutronix.de,
        linux-usb@vger.kernel.org, x86@kernel.org,
        linux-kernel@vger.kernel.org, Jiri Slaby <jslaby@suse.cz>
Subject: Re: [PATCH v5 1/4] usb: dbc: early driver for xhci debug capability
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* Lu Baolu <baolu.lu@linux.intel.com> wrote:

> Hi Ingo,
> 
> On 01/26/2017 03:19 PM, Ingo Molnar wrote:
> > * Lu Baolu <baolu.lu@linux.intel.com> 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!

Thanks,

	Ingo