[PATCH AUTOSEL 6.18-6.12] Bluetooth: btusb: MT7922: Add VID/PID 0489/e170

[Sasha Levin <sashal@kernel.org>]

From: Chris Lu <chris.lu@mediatek.com>

[ Upstream commit 5a6700a31c953af9a17a7e2681335f31d922614d ]

Add VID 0489 & PID e170 for MediaTek MT7922 USB Bluetooth chip.

The information in /sys/kernel/debug/usb/devices about the Bluetooth
device is listed as the below.

T:  Bus=06 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#=  2 Spd=480  MxCh= 0
D:  Ver= 2.10 Cls=ef(misc ) Sub=02 Prot=01 MxPS=64 #Cfgs=  1
P:  Vendor=0489 ProdID=e170 Rev= 1.00
S:  Manufacturer=MediaTek Inc.
S:  Product=Wireless_Device
S:  SerialNumber=000000000
C:* #Ifs= 3 Cfg#= 1 Atr=e0 MxPwr=100mA
A:  FirstIf#= 0 IfCount= 3 Cls=e0(wlcon) Sub=01 Prot=01
I:* If#= 0 Alt= 0 #EPs= 3 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E:  Ad=81(I) Atr=03(Int.) MxPS=  16 Ivl=125us
E:  Ad=82(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=02(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
I:* If#= 1 Alt= 0 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E:  Ad=83(I) Atr=01(Isoc) MxPS=   0 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=   0 Ivl=1ms
I:  If#= 1 Alt= 1 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E:  Ad=83(I) Atr=01(Isoc) MxPS=   9 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=   9 Ivl=1ms
I:  If#= 1 Alt= 2 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E:  Ad=83(I) Atr=01(Isoc) MxPS=  17 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=  17 Ivl=1ms
I:  If#= 1 Alt= 3 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E:  Ad=83(I) Atr=01(Isoc) MxPS=  25 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=  25 Ivl=1ms
I:  If#= 1 Alt= 4 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E:  Ad=83(I) Atr=01(Isoc) MxPS=  33 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=  33 Ivl=1ms
I:  If#= 1 Alt= 5 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E:  Ad=83(I) Atr=01(Isoc) MxPS=  49 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=  49 Ivl=1ms
I:  If#= 1 Alt= 6 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E:  Ad=83(I) Atr=01(Isoc) MxPS=  63 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=  63 Ivl=1ms
I:* If#= 2 Alt= 0 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=(none)
E:  Ad=8a(I) Atr=03(Int.) MxPS=  64 Ivl=125us
E:  Ad=0a(O) Atr=03(Int.) MxPS=  64 Ivl=125us
I:  If#= 2 Alt= 1 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=(none)
E:  Ad=8a(I) Atr=03(Int.) MxPS= 512 Ivl=125us
E:  Ad=0a(O) Atr=03(Int.) MxPS= 512 Ivl=125us

Signed-off-by: Chris Lu <chris.lu@mediatek.com>
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

LLM Generated explanations, may be completely bogus:

## Analysis: Bluetooth: btusb: MT7922: Add VID/PID 0489/e170

### 1. COMMIT MESSAGE ANALYSIS

**Subject**: Adding a new USB Vendor ID (VID) 0x0489 and Product ID
(PID) 0xe170 for a MediaTek MT7922 Bluetooth chip.

**Key Tags**:
- Signed-off-by: Chris Lu from MediaTek (the chip vendor)
- Reviewed-by: Paul Menzel
- Signed-off-by: Luiz Augusto von Dentz (Bluetooth maintainer)

No explicit `Cc: stable@vger.kernel.org` tag, but this is common for
device ID additions which are often handled implicitly.

### 2. CODE CHANGE ANALYSIS

The change is a 2-line addition to the `quirks_table[]` array:
```c
{ USB_DEVICE(0x0489, 0xe170), .driver_info = BTUSB_MEDIATEK |
                                             BTUSB_WIDEBAND_SPEECH },
```

This simply registers a new USB device ID with existing driver flags
(`BTUSB_MEDIATEK` and `BTUSB_WIDEBAND_SPEECH`) that are already fully
supported. The btusb driver already contains full MT7922 support - this
just adds another VID/PID variant to the recognition table.

### 3. CLASSIFICATION

This is a **NEW DEVICE ID** addition - one of the explicitly allowed
exception categories for stable backports:
- Adding a USB VID/PID to an existing, well-tested driver
- Trivial one-entry addition to a device table
- The driver code for MT7922 already exists; only recognition is missing

### 4. SCOPE AND RISK ASSESSMENT

| Metric | Assessment |
|--------|------------|
| Lines changed | 2 |
| Files touched | 1 |
| Complexity | Minimal - static table entry |
| Risk | **Extremely low** |

The change can only affect USB devices with VID=0x0489 and PID=0xe170.
Users without this specific hardware are completely unaffected. This is
about as low-risk as a kernel patch can be.

### 5. USER IMPACT

- **Affected users**: Those with this specific MediaTek MT7922 Bluetooth
  variant
- **Severity without fix**: Bluetooth hardware is completely non-
  functional (driver doesn't recognize the device)
- **Impact**: HIGH for affected users - their Bluetooth doesn't work at
  all

The commit includes detailed `/sys/kernel/debug/usb/devices` output
showing real hardware, indicating this comes from actual user/vendor
testing.

### 6. STABILITY INDICATORS

- Authored by MediaTek (chip vendor) with direct hardware knowledge
- Reviewed by community member
- Signed off by the Bluetooth subsystem maintainer
- Follows established pattern of many similar MT7922 device ID entries
  visible in the diff context

### 7. DEPENDENCY CHECK

- **No dependencies**: This is a self-contained table entry addition
- **Existing support**: The BTUSB_MEDIATEK and BTUSB_WIDEBAND_SPEECH
  flags and MT7922 support code exist in all recent stable trees
- **Clean application**: Should apply cleanly to any stable tree that
  has MT7922 support

### CONCLUSION

This commit is a textbook example of what SHOULD be backported to
stable:

1. **Falls under Device ID Exception**: Explicitly allowed category for
   stable
2. **Fixes Real User Problem**: Enables Bluetooth hardware that would
   otherwise be completely non-functional
3. **Minimal Risk**: 2-line table entry addition, cannot break anything
   else
4. **No New Features**: Just enables existing driver for new hardware
   variant
5. **Well-Reviewed**: Proper sign-offs from vendor and maintainer
6. **Clear Benefit**: Users with this hardware get working Bluetooth

The lack of explicit stable tag is typical for device ID additions -
stable maintainers routinely accept these. The benefit (enabling
hardware) far outweighs the near-zero risk.

**YES**

 drivers/bluetooth/btusb.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 595afeff4afb5..9b199da1c0d67 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -687,6 +687,8 @@ static const struct usb_device_id quirks_table[] = {
 						     BTUSB_WIDEBAND_SPEECH },
 	{ USB_DEVICE(0x0489, 0xe153), .driver_info = BTUSB_MEDIATEK |
 						     BTUSB_WIDEBAND_SPEECH },
+	{ USB_DEVICE(0x0489, 0xe170), .driver_info = BTUSB_MEDIATEK |
+						     BTUSB_WIDEBAND_SPEECH },
 	{ USB_DEVICE(0x04ca, 0x3804), .driver_info = BTUSB_MEDIATEK |
 						     BTUSB_WIDEBAND_SPEECH },
 	{ USB_DEVICE(0x04ca, 0x38e4), .driver_info = BTUSB_MEDIATEK |
-- 
2.51.0