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From:   Xie He <xie.he.0141@gmail.com>
Date:   Thu, 5 Nov 2020 11:35:05 -0800
Message-ID: <CAJht_EM6rXw2Y6NOw9npqUx-MSscwaZ54q7KM4V2ip_CCQsdeg@mail.gmail.com>
Subject: Re: [PATCH net-next] net: x25_asy: Delete the x25_asy driver
To:     David Laight <David.Laight@aculab.com>
Cc:     Jakub Kicinski <kuba@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Arnd Bergmann <arnd@arndb.de>
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On Thu, Nov 5, 2020 at 1:10 AM David Laight <David.Laight@aculab.com> wrote:
>
> > This driver transports LAPB (X.25 link layer) frames over TTY links.
>
> I don't remember any requests to run LAPB over anything other
> than synchronous links when I was writing LAPB implementation(s)
> back in the mid 1980's.
>
> If you need to run 'comms over async uart links' there
> are better options.
>
> I wonder what the actual use case was?

I think this driver was just for experimental purposes. According to
the author's comment at the beginning of x25_asy.c, this driver didn't
implement FCS (frame check sequence), which was required by CCITT's
standard. So I think this driver was not suitable for real-world use
anyway.