[PATCH 6.6 011/105] can: gs_usb: gs_make_candev(): populate net_device->dev_port

Greg Kroah-Hartman
2025-10-21T19:55:08Z

From: Celeste Liu <uwu@coelacanthus.name>

commit a12f0bc764da3781da2019c60826f47a6d7ed64f upstream.

The gs_usb driver supports USB devices with more than 1 CAN channel.
In old kernel before 3.15, it uses net_device->dev_id to distinguish
different channel in userspace, which was done in commit
acff76fa45b4 ("can: gs_usb: gs_make_candev(): set netdev->dev_id").
But since 3.15, the correct way is populating net_device->dev_port.
And according to documentation, if network device support multiple
interface, lack of net_device->dev_port SHALL be treated as a bug.

Fixes: acff76fa45b4 ("can: gs_usb: gs_make_candev(): set netdev->dev_id")
Cc: stable@vger.kernel.org
Signed-off-by: Celeste Liu <uwu@coelacanthus.name>
Link: https://patch.msgid.link/20250930-gs-usb-populate-net_device-dev_port-v1-1-68a065de6937@coelacanthus.name
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/can/usb/gs_usb.c | 1 +
1 file changed, 1 insertion(+)

--- a/drivers/net/can/usb/gs_usb.c
+++ b/drivers/net/can/usb/gs_usb.c
@@ -1246,6 +1246,7 @@ static struct gs_can *gs_make_candev(uns

netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
netdev->dev_id = channel;
+ netdev->dev_port = channel;

/* dev setup */
strcpy(dev->bt_const.name, KBUILD_MODNAME);