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Date:   Mon, 27 Jun 2022 15:37:10 -0400
From:   Alan Stern <stern@rowland.harvard.edu>
To:     Matthias Kaehlcke <mka@chromium.org>
Cc:     Doug Anderson <dianders@chromium.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Rob Herring <robh+dt@kernel.org>,
        Frank Rowand <frowand.list@gmail.com>,
        Mathias Nyman <mathias.nyman@intel.com>,
        Felipe Balbi <balbi@kernel.org>,
        Michal Simek <michal.simek@xilinx.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Krzysztof Kozlowski <krzk@kernel.org>,
        Stephen Boyd <swboyd@chromium.org>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>, Bastien Nocera <hadess@hadess.net>,
        Peter Chen <peter.chen@kernel.org>,
        Ravi Chandra Sadineni <ravisadineni@chromium.org>,
        Roger Quadros <rogerq@kernel.org>,
        Linux USB List <linux-usb@vger.kernel.org>,
        Geert Uytterhoeven <geert+renesas@glider.be>,
        Souradeep Chowdhury <quic_schowdhu@quicinc.com>
Subject: Re: [PATCH v22 2/3] usb: misc: Add onboard_usb_hub driver
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On Mon, Jun 27, 2022 at 12:06:21PM -0700, Matthias Kaehlcke wrote:
> On Mon, Jun 27, 2022 at 02:54:03PM -0400, Alan Stern wrote:
> > On Mon, Jun 27, 2022 at 11:14:47AM -0700, Matthias Kaehlcke wrote:
> > > 
> > >   Further there must be only one platform device for onboard hubs with a
> > >   companion hub (the hub is a single physical device). To achieve this two
> > 
> > What do you mean by "companion hub"?  I think you are using the wrong 
> > word here.  If you're talking about the relation between the two logical 
> > hubs (one attached to the SuperSpeed bus and one attached to the 
> > Low/Full/High-speed bus) within a physical USB-3 hub, the correct term 
> > for this is "peer".  See the existing usages in hub.h, hub.c, and 
> > port.c.
> > 
> > "Companion" refers to something completely different (i.e., the UHCI or 
> > OHCI controllers that handle Low/Full-speed connections on behalf of a 
> > High-speed EHCI controller).
> 
> Yes it's the relation between the two logical hub. The term 'companion-hub'
> stems from the binding and has been around since v6 of this series. I guess
> we should update the binding if the terminology isn't correct.

That sounds like a good idea.

Alan Stern