On Mon, Jan 5, 2026 at 11:21 AM Slark Xiao <slark_xiao@163.com> wrote:
>
> From: Sergey Ryazanov <ryazanov.s.a@gmail.com>
>
> Upcoming GNSS (NMEA) port type support requires exporting it via the
> GNSS subsystem. On another hand, we still need to do basic WWAN core
> work: call the port stop operation, purge queues, release the parent
> WWAN device, etc. To reuse as much code as possible, split the port
> unregistering function into the deregistration of a regular WWAN port
> device, and the common port tearing down code.
>
> In order to keep more code generic, break the device_unregister() call
> into device_del() and put_device(), which release the port memory
> uniformly.
>
> Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Reviewed-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
> ---
> drivers/net/wwan/wwan_core.c | 23 ++++++++++++++++++-----
> 1 file changed, 18 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/net/wwan/wwan_core.c b/drivers/net/wwan/wwan_core.c
> index edee5ff48f28..c735b9830e6e 100644
> --- a/drivers/net/wwan/wwan_core.c
> +++ b/drivers/net/wwan/wwan_core.c
> @@ -476,6 +476,18 @@ static int wwan_port_register_wwan(struct wwan_port *port)
> return 0;
> }
>
> +/* Unregister a regular WWAN port (e.g. AT, MBIM, etc) */
> +static void wwan_port_unregister_wwan(struct wwan_port *port)
> +{
> + struct wwan_device *wwandev = to_wwan_dev(port->dev.parent);
> +
> + dev_set_drvdata(&port->dev, NULL);
> +
> + dev_info(&wwandev->dev, "port %s disconnected\n", dev_name(&port->dev));
> +
> + device_del(&port->dev);
> +}
> +
> struct wwan_port *wwan_create_port(struct device *parent,
> enum wwan_port_type type,
> const struct wwan_port_ops *ops,
> @@ -536,18 +548,19 @@ void wwan_remove_port(struct wwan_port *port)
> struct wwan_device *wwandev = to_wwan_dev(port->dev.parent);
>
> mutex_lock(&port->ops_lock);
> - if (port->start_count)
> + if (port->start_count) {
> port->ops->stop(port);
> + port->start_count = 0;
> + }
> port->ops = NULL; /* Prevent any new port operations (e.g. from fops) */
> mutex_unlock(&port->ops_lock);
>
> wake_up_interruptible(&port->waitqueue);
> -
> skb_queue_purge(&port->rxq);
> - dev_set_drvdata(&port->dev, NULL);
>
> - dev_info(&wwandev->dev, "port %s disconnected\n", dev_name(&port->dev));
> - device_unregister(&port->dev);
> + wwan_port_unregister_wwan(port);
> +
> + put_device(&port->dev);
>
> /* Release related wwan device */
> wwan_remove_dev(wwandev);
> --
> 2.25.1
>