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From:   Xie He <xie.he.0141@gmail.com>
Date:   Fri, 20 Nov 2020 15:50:31 -0800
Message-ID: <CAJht_EP_oqCDs6mMThBZNtz4sgpbyQgMhKkHeqfS_7JmfEzfQg@mail.gmail.com>
Subject: Re: [PATCH net-next v4 2/5] net/lapb: support netdev events
To:     Martin Schiller <ms@dev.tdt.de>
Cc:     Andrew Hendry <andrew.hendry@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Linux X25 <linux-x25@vger.kernel.org>,
        Linux Kernel Network Developers <netdev@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
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On Fri, Nov 20, 2020 at 3:11 PM Xie He <xie.he.0141@gmail.com> wrote:
>
> Should we also handle the NETDEV_UP event here? In previous versions
> of this patch series you seemed to want to establish the L2 connection
> on device-up. But in this patch, you didn't handle NETDEV_UP.
>
> Maybe on device-up, we need to check if the carrier is up, and if it
> is, we do the same thing as we do on carrier-up.

Are the device up/down status and the carrier up/down status
independent of each other? If they are, on device-up or carrier-up, we
only need to try establishing the L2 connection if we see both are up.

On NETDEV_GOING_DOWN, we can also check the carrier status first and
if it is down, we don't need to call lapb_disconnect_request.