Re: [PATCH 4/5] i3c: slave: func: add tty driver

Jiri Slaby
2023-10-19T20:33:22Z

On 18. 10. 23, 23:58, Frank Li wrote:
> Add tty over I3C slave function driver.

Many of the master review comments apply also here. Please fix here too.
More below.

> --- /dev/null
> +++ b/drivers/i3c/func/tty.c
> @@ -0,0 +1,548 @@
...
> +static void i3c_slave_tty_rx_complete(struct i3c_request *req)
> +{
> + struct ttyi3c_port *port = req->context;
> +
> + if (req->status == I3C_REQUEST_CANCEL) {
> + i3c_slave_ctrl_free_request(req);
> + return;
> + }
> +
> + for (int i = 0; i < req->actual; i++)
> + tty_insert_flip_char(&port->port, *(u8 *)(req->buf + i), 0);

Maybe I miss something obvious, but req->buf is void *. So why not
simple tty_insert_flip_string()?

> + sport->buffer = (void *)get_zeroed_page(GFP_KERNEL);
> + if (!sport->buffer)
> + return -ENOMEM;
> +
> + sport->xmit.buf = (void *)get_zeroed_page(GFP_KERNEL);

tty_port_alloc_xmit_buf()

> +static int i3c_tty_probe(struct i3c_slave_func *func)
> +{
> + struct device *dev = &func->dev;
> + struct ttyi3c_port *port;
> +
> + port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
> + if (!port)
> + return -ENOMEM;
> +
> + port->i3cdev = func;
> + dev_set_drvdata(&func->dev, port);
> +
> + port->workqueue = alloc_workqueue("%s", 0, 0, dev_name(&func->dev));

Another wq? You'd have to have a strong reason for these. Drop that.

> + if (!port->workqueue)
> + return -ENOMEM;
> +
> + INIT_WORK(&port->work, i3c_slave_tty_i3c_work);
> +
> + return 0;
> +}
> +
> +static void i3c_tty_remove(struct i3c_slave_func *func)
> +{
> + struct ttyi3c_port *port;
> +
> + port = dev_get_drvdata(&func->dev);

That can be on one line.

> +
> + destroy_workqueue(port->workqueue);
> +}

> +static int i3c_open(struct tty_struct *tty, struct file *filp)
> +{
> + struct ttyi3c_port *sport = tty->driver_data;
> + int ret;
> +
> + if (!i3c_slave_ctrl_get_addr(sport->i3cdev->ctrl)) {
> + dev_info(&sport->i3cdev->dev, "No slave addr assigned, try hotjoin");

Should this be a debug print instead?

> + ret = i3c_slave_ctrl_hotjoin(sport->i3cdev->ctrl);
> + if (ret) {
> + dev_err(&sport->i3cdev->dev, "Hotjoin failure, check connection");
> + return ret;
> + }
> + }
> +
> + return tty_port_open(&sport->port, tty, filp);

regards,
--
js
suse labs