From: Valentin Spreckels <redacted>

[ Upstream commit 15fba71533bcdfaa8eeba69a5a5a2927afdf664a ]

The TRENDnet TUC-ET2G is a RTL8156 based usb ethernet adapter. Add its
vendor and product IDs.

Signed-off-by: Valentin Spreckels <redacted>
Link: https://patch.msgid.link/20260226195409.7891-2-valentin@spreckels.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

LLM Generated explanations, may be completely bogus:

## Analysis

### What the commit does

This commit adds USB vendor and product IDs for the TRENDnet TUC-ET2G
USB ethernet adapter (vendor ID `0x20f4`, product ID `0xe02b`) to the
existing `r8152` driver. The device uses the RTL8156 chipset, which is
already fully supported by the driver.

### Changes

1. **`include/linux/usb/r8152.h`**: Adds `#define VENDOR_ID_TRENDNET
   0x20f4`
2. **`drivers/net/usb/r8152.c`**: Adds `{ USB_DEVICE(VENDOR_ID_TRENDNET,
   0xe02b) }` to the device table

### Stable kernel criteria

- **New device ID to existing driver**: This is a textbook example of
  the "NEW DEVICE IDs" exception explicitly listed in stable kernel
  rules. The r8152 driver already exists in all stable trees, and the
  RTL8156 chipset is already supported.
- **Obviously correct**: Two lines — a vendor ID define and a device
  table entry.
- **No risk of regression**: Adding a USB device ID cannot break
  existing functionality. It only enables matching for a new device.
- **Small and contained**: 2 lines of actual change across 2 files.
- **Fixes a real problem**: Without this, users with TRENDnet TUC-ET2G
  adapters cannot use them with the r8152 driver (the device won't be
  claimed).

### Risk assessment

**Zero risk.** This is the most minimal possible change — adding
identifiers so the kernel recognizes a device. No code paths are
changed, no logic is modified.

### Verification

- Confirmed `VENDOR_ID_TRENDNET` is a new define not previously in the
  header by examining the diff context showing the existing vendor IDs.
- The RTL8156 chipset support already exists in the r8152 driver (the
  driver handles RTL8152/8153/8156 variants).
- The change pattern matches dozens of similar device ID additions that
  are routinely backported to stable (e.g., other vendor IDs already in
  the table: Lenovo, Linksys, NVIDIA, TP-Link, D-Link, Dell, ASUS).
- No dependencies on other commits — this is fully self-contained.

**YES**

 drivers/net/usb/r8152.c   | 1 +
 include/linux/usb/r8152.h | 1 +
 2 files changed, 2 insertions(+)

diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index 6b107cf5f37bd..9eda892beb1f8 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c

@@ -10062,6 +10062,7 @@ static const struct usb_device_id rtl8152_table[] = {
 	{ USB_DEVICE(VENDOR_ID_DLINK,   0xb301) },
 	{ USB_DEVICE(VENDOR_ID_DELL,    0xb097) },
 	{ USB_DEVICE(VENDOR_ID_ASUS,    0x1976) },
+	{ USB_DEVICE(VENDOR_ID_TRENDNET, 0xe02b) },
 	{}
 };
 

diff --git a/include/linux/usb/r8152.h b/include/linux/usb/r8152.h
index 2ca60828f28bb..1502b2a355f98 100644
--- a/include/linux/usb/r8152.h
+++ b/include/linux/usb/r8152.h

@@ -32,6 +32,7 @@
 #define VENDOR_ID_DLINK			0x2001
 #define VENDOR_ID_DELL			0x413c
 #define VENDOR_ID_ASUS			0x0b05
+#define VENDOR_ID_TRENDNET		0x20f4
 
 #if IS_REACHABLE(CONFIG_USB_RTL8152)
 extern u8 rtl8152_get_version(struct usb_interface *intf);

-- 
2.51.0