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

[Jiri Slaby <jirislaby@kernel.org>]

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@pengutronix.de>
> ---
>   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?

thanks,
-- 
js
suse labs