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From:   Peter Chen <hzpeterchen@gmail.com>
Date:   Sun, 29 Sep 2019 14:29:04 +0800
Message-ID: <CAL411-rPQiMN15-yTDTcNzhy9bvo_XnvYQFwKQTJ779MG8gBtQ@mail.gmail.com>
Subject: Re: [PATCH] usb: hub add filter for device with specific VID&PID
To:     Ran Wang <ran.wang_1@nxp.com>
Cc:     Alan Stern <stern@rowland.harvard.edu>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Kai-Heng Feng <kai.heng.feng@canonical.com>,
        Mathias Nyman <mathias.nyman@linux.intel.com>,
        Mathias Payer <mathias.payer@nebelwelt.net>,
        Dennis Wassenberg <dennis.wassenberg@secunet.com>,
        "open list:USB SUBSYSTEM" <linux-usb@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>
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> > >
> > > In fact, the system should respond the same way to any unrecognized
> > > device that doesn't support HNP, right?  There's nothing special about
> > > these VID/PID values.
> >
> > Yes, but I saw there are already some implementation in upstream kernel for this
> > purpose, just PID different: drivers/usb/core/otg_whitelist.h function
> > is_targeted()
> >
> > > > > And why those specific vid/pid values?  What do they refer to?
> > > >
> > > > For step 5, we got the VID / PID number from USB IF certified
> > > > lab(Allion.inc at Taiwang). Looks like this is a reserved ID pair
> > > > and will not be allocated to any vendor for their products. So it's
> > > > hence used for
> > > this case test (like saying: you should be able to pop a not-support
> > > message for this reserved VID&PID).
> > >
> > > Don't we do this already?
> >
> > Yes, but in function is_stargeted(), I found it's a little be different:
> > Current upstream:                     VID = 0x1a0a, PID = 0x0200
> > Info from USB-IF certified lab: VID = 0x1a0a, PID = 0x0201
> >
>
> Sorry that I mis-understood the logic of is_stargeted() and it's caller.
>
> So the proper way to resolve my problem is:
> 1. Select CONFIG_USB_OTG in .config
> 2. Add property 'tpl-support' to device tree
> 3. Customize whitelist_table[] according to my Target-Peripheral-List
> requirement.
>

Yan, this is the correct way, we (NXP i.MX Series) have followed this
way for USB EH certification
several years.

Peter

> Am I right? :)
>
> Regards,
> Ran