Re: [PATCH] usbnet: prevent device rpm suspend in usbnet_probe function

From: Oliver Neukum
Date: Thu Nov 10 2016 - 06:28:32 EST


On Thu, 2016-11-10 at 12:09 +0100, BjÃrn Mork wrote:
> Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> writes:
> > On Wed, Nov 9, 2016 at 8:32 PM, BjÃrn Mork <bjorn@xxxxxxx> wrote:
> >> Oliver Neukum <oneukum@xxxxxxxx> writes:
> >>
> >>> On Tue, 2016-11-08 at 13:44 -0500, Alan Stern wrote:
> >>>
> >>>> These problems could very well be caused by running at SuperSpeed
> >>>> (USB-3) instead of high speed (USB-2).
> >
> > Yes, it's running at SuperSpeed, on a Kabylake laptop.
> >
> > It does not have this issue on a Broadwell laptop, also running at SuperSpeed.
>
> Then I must join Oliver, being very surprised by where in the stack you
> attempt to fix the issue. What you write above indicates a problem in
> pci bridge or usb host controller, doesn't it?

Indeed. And this means we need an XHCI specialist.
Mathias, we have a failure specific to one implementation of XHCI.

Regards
Oliver