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In-Reply-To: <e1750da4179aca52960703890e985af3@dev.tdt.de>
From:   Xie He <xie.he.0141@gmail.com>
Date:   Fri, 26 Feb 2021 15:03:11 -0800
Message-ID: <CAJht_ENP3Y98jgj1peGa3fGpQ-qPaF=1gtyYwMcawRFW_UCpeA@mail.gmail.com>
Subject: Re: [PATCH net-next RFC v4] net: hdlc_x25: Queue outgoing LAPB frames
To:     Martin Schiller <ms@dev.tdt.de>
Cc:     Jakub Kicinski <kuba@kernel.org>,
        Leon Romanovsky <leon@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        Linux X25 <linux-x25@vger.kernel.org>,
        Linux Kernel Network Developers <netdev@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Krzysztof Halasa <khc@pm.waw.pl>,
        Jonathan Corbet <corbet@lwn.net>, linux-doc@vger.kernel.org
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On Fri, Feb 26, 2021 at 6:21 AM Martin Schiller <ms@dev.tdt.de> wrote:
>
> I have now had a look at it. It works as expected.
> I just wonder if it would not be more appropriate to call
> the lapb_register() already in x25_hdlc_open(), so that the layer2
> (lapb) can already "work" before the hdlc<x>_x25 interface is up.

I think it's better not to keep LAPB running unless hdlc<x>_x25 is up.
If I am the user, I would expect that when I change the X.25 interface
to the DOWN state, the LAPB protocol would be completely stopped and
the LAPB layer would not generate any new frames anymore (even if the
other side wants to connect), and when I change the X.25 interface
back to the UP state, it would be a fresh new start for the LAPB
protocol.

> Also, I have a hard time assessing if such a wrap is really enforceable.

Sorry. I don't understand what you mean. What "wrap" are you referring to?

> Unfortunately I have no idea how many users there actually are.