Re: [PATCH 1/3] serdev: ttyport: make use of tty_kopen_exclusive

From: Marco Felsch
Date: Wed Aug 21 2024 - 03:26:47 EST


On 24-08-08, Jiri Slaby wrote:
> On 07. 08. 24, 16:08, Marco Felsch wrote:
> > The purpose of serdev is to provide kernel drivers for particular serial
> > device, serdev-ttyport is no exception here. Make use of the
> > tty_kopen_exclusive() funciton to mark this tty device as kernel
> > internal device.
> >
> > Signed-off-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx>
> > ---
> > drivers/tty/serdev/serdev-ttyport.c | 9 ++++++---
> > 1 file changed, 6 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/tty/serdev/serdev-ttyport.c b/drivers/tty/serdev/serdev-ttyport.c
> > index 3d7ae7fa5018..94c43d25ddbe 100644
> > --- a/drivers/tty/serdev/serdev-ttyport.c
> > +++ b/drivers/tty/serdev/serdev-ttyport.c
> > @@ -103,11 +103,14 @@ static int ttyport_write_room(struct serdev_controller *ctrl)
> > static int ttyport_open(struct serdev_controller *ctrl)
> > {
> > struct serport *serport = serdev_controller_get_drvdata(ctrl);
> > + struct tty_driver *tty_drv = serport->tty_drv;
> > struct tty_struct *tty;
> > struct ktermios ktermios;
> > + dev_t dev;
> > int ret;
> > - tty = tty_init_dev(serport->tty_drv, serport->tty_idx);
> > + dev = MKDEV(tty_drv->major, tty_drv->minor_start + serport->tty_idx);
> > + tty = tty_kopen_exclusive(dev);
>
> I believe that the now added tty_lookup_driver() has negligible impact in
> this anyway slow path, right?

Any other comments, suggestions apart this one?

Regards,
Marco

>
> thanks,
> --
> js
> suse labs
>
>