r8152: Add Lenovo Powered USB-C Travel Hub

commit cb82a54 upstream.

This USB-C Hub (17ef:721e) based on the Realtek RTL8153B chip used to
use the cdc_ether driver. However, using this driver, with the system
suspended the device constantly sends pause-frames as soon as the
receive buffer fills up. This causes issues with other devices, where
some Ethernet switches stop forwarding packets altogether.

Using the Realtek driver (r8152) fixes this issue. Pause frames are no
longer sent while the host system is suspended.

Signed-off-by: Leon Schuermann <leon@is.currently.online>
Tested-by: Leon Schuermann <leon@is.currently.online>
Link: https://lore.kernel.org/r/20210111190312.12589-2-leon@is.currently.online
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/net/usb/cdc_ether.c

@@ -793,6 +793,13 @@ static const struct usb_device_id	products[] = {
 	.driver_info = 0,
 },
 
+/* Lenovo Powered USB-C Travel Hub (4X90S92381, based on Realtek RTL8153) */
+{
+	USB_DEVICE_AND_INTERFACE_INFO(LENOVO_VENDOR_ID, 0x721e, USB_CLASS_COMM,
+			USB_CDC_SUBCLASS_ETHERNET, USB_CDC_PROTO_NONE),
+	.driver_info = 0,
+},
+
 /* ThinkPad USB-C Dock Gen 2 (based on Realtek RTL8153) */
 {
 	USB_DEVICE_AND_INTERFACE_INFO(LENOVO_VENDOR_ID, 0xa387, USB_CLASS_COMM,

drivers/net/usb/r8152.c

@@ -6893,6 +6893,7 @@ static const struct usb_device_id rtl8152_table[] = {
 	{REALTEK_USB_DEVICE(VENDOR_ID_LENOVO,  0x7205)},
 	{REALTEK_USB_DEVICE(VENDOR_ID_LENOVO,  0x720c)},
 	{REALTEK_USB_DEVICE(VENDOR_ID_LENOVO,  0x7214)},
+	{REALTEK_USB_DEVICE(VENDOR_ID_LENOVO,  0x721e)},
 	{REALTEK_USB_DEVICE(VENDOR_ID_LENOVO,  0xa387)},
 	{REALTEK_USB_DEVICE(VENDOR_ID_LINKSYS, 0x0041)},
 	{REALTEK_USB_DEVICE(VENDOR_ID_NVIDIA,  0x09ff)},