[PATCH AUTOSEL 4.14 4/9] r8152: Add Lenovo Powered USB-C Travel Hub

[PATCH AUTOSEL 4.14 4/9] r8152: Add Lenovo Powered USB-C Travel Hub

[Sasha Levin]

From: Leon Schuermann <leon@is.currently.online>

[ Upstream commit cb82a54904a99df9e8f9e9d282046055dae5a730 ]

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: Sasha Levin <sashal@kernel.org>
---
 drivers/net/usb/cdc_ether.c | 7 +++++++
 drivers/net/usb/r8152.c     | 1 +
 2 files changed, 8 insertions(+)

diff --git a/drivers/net/usb/cdc_ether.c b/drivers/net/usb/cdc_ether.c
index f3def96d35d42..8c9eae5f30722 100644
--- a/drivers/net/usb/cdc_ether.c
+++ b/drivers/net/usb/cdc_ether.c
@@ -800,6 +800,13 @@ 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,
diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index e30792380812a..bd91d4bad49b2 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -5337,6 +5337,7 @@ 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)},
-- 
2.27.0