Re: [PATCH v9] can, tty: can327 CAN/ldisc driver for ELM327 based OBD-II adapters

From: Geert Uytterhoeven
Date: Tue Jul 05 2022 - 06:16:30 EST


Hi Marc, Max,

On Tue, Jul 5, 2022 at 11:56 AM Max Staudt <max@xxxxxxxxx> wrote:
> On Tue, 5 Jul 2022 11:49:27 +0200
> Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> wrote:
> > On 05.07.2022 11:43:52, Geert Uytterhoeven wrote:
> > > So development started before commit cd6484e1830be260 ("serdev:
> > > Introduce new bus for serial attached devices"). I guess that is
> > > the reason why this driver uses a line discipline, instead of the
> > > serial bus?
> > >
> > > I had a quick glance through the various revisions posted, and it
> > > doesn't seem like anyone mentioned the serial bus. Would there be
> > > any advantage in migrating to the serial bus?
> >
> > Does serial bus work with hot plug devices like USB Serial Adapters
> > and/or devices that are not described in the device tree?

Probably it cannot work with hot-plug devices yet.
And devices must be described in some way (DT, ACPI), it does not
support auto-detect.

> This is indeed the reason. The device cannot be autodetected, as the
> UART has no identifying information (USB VID/PID or the like, and don't
> forget the BT variants) attached to it, hence the manual attachment.

So you do need a description ;-)

So far I've seen serial bus used with e.g. bluetooth and DT.
I'm wondering if/how people use it with bluetooth connected to a
hot-pluggable device like usb-serial.

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds