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Date:   Tue, 15 Sep 2020 13:01:11 +0200
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Eugeniu Rosca <erosca@de.adit-jv.com>
Cc:     Alan Stern <stern@rowland.harvard.edu>, linux-usb@vger.kernel.org,
        linux-kernel@vger.kernel.org, andrew_gabbasov@mentor.com,
        Baxter Jim <jim_baxter@mentor.com>,
        "Natsume, Wataru (ADITJ/SWG)" <wnatsume@jp.adit-jv.com>,
        "Nishiguchi, Naohiro (ADITJ/SWG)" <nnishiguchi@jp.adit-jv.com>,
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        kernel test robot <rong.a.chen@intel.com>,
        yasushi asano <yazzep@gmail.com>,
        Martin Mueller <Martin.Mueller5@de.bosch.com>,
        Eugeniu Rosca <roscaeugeniu@gmail.com>
Subject: Re: [PATCH v3] USB: hub.c: decrease the number of attempts of
 enumeration scheme
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On Tue, Sep 15, 2020 at 11:45:31AM +0200, Eugeniu Rosca wrote:
> Dear Alan,
> Dear Greg,
> 
> On Fri, Sep 11, 2020 at 11:12:28AM -0400, Alan Stern wrote:
> 
> > The thing is, I'm afraid that without these retry loops, some devices
> > will stop working.  If that happens, we will not be able to keep this
> > patch in place; we will just have to accept that we fail the PET test.
> > 
> > Alan Stern
> 
> Does this mean that Linux community leaves no choice but to ship a
> forked kernel (with no chance of alignment to upstream) for
> organizations which design embedded devices where USB plays a key
> role, hence requires passing the USB-IF Compliance Program [*]?

We are saying that if you ship such a kernel, we _KNOW_ that it will
fail to work in a number of known systems.  I doubt you want that to
happen if you care about shipping a device, right?

> Is there hope to give users a knob (build-time or run-time) which would
> enable the behavior expected and thoroughly described in compliance
> docs, particularly chapter "6.7.22 A-UUT Device No Response for
> connection timeout" of "USB On-The-Go and Embedded Host Automated
> Compliance Plan" [**]?

Given that the USB-IF has explicitly kicked-out the Linux community from
its specification work and orginization, I personally don't really care
what they say here.  If you are a member of the USB-IF, please work with
them to fix the test to reflect real-world systems and not an idealized
system.  Last I heard, they wanted nothing to do with Linux systems at
all :(

thanks,

greg k-h