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Date:   Fri, 13 May 2022 13:52:23 +0200
From:   Marc Kleine-Budde <mkl@pengutronix.de>
To:     Vincent Mailhol <vincent.mailhol@gmail.com>
Cc:     Max Staudt <max@enpas.org>,
        Wolfgang Grandegger <wg@grandegger.com>,
        linux-can@vger.kernel.org,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Oliver Neukum <oneukum@suse.com>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v6] can, tty: can327 CAN/ldisc driver for ELM327 based
 OBD-II adapters
Message-ID: <20220513115223.b56etkaejphldjok@pengutronix.de>
References: <20220512182921.193462-1-max@enpas.org>
 <CAMZ6Rq+BwL1NPTLtC5sQAd4z1Kc1TFJPPoW-i+0RZ5dnFaWYiw@mail.gmail.com>
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On 13.05.2022 11:38:31, Vincent Mailhol wrote:
> > +
> > +       /* We shouldn't get here after a hardware fault:
> > +        * can_bus_off() calls netif_carrier_off()
> > +        */
> > +       WARN_ON_ONCE(elm->uart_side_failure);
> > +
> > +       if (!elm->tty ||
> > +           elm->uart_side_failure ||
> > +           elm->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) {
>=20
> Can the xmit function get called when CAN_CTRLMODE_LISTENONLY is on?

I think yes. You can skip the whole CAN stack by injecting CAN frames in
the kernel via the packet socket. Maybe we should add a check to
can_dropped_invalid_skb().

Marc

--=20
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
Vertretung West/Dortmund         | Phone: +49-231-2826-924     |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-5555 |

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