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

From: Jiri Slaby
Date: Thu Aug 08 2024 - 03:52:14 EST


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?

thanks,
--
js
suse labs