[PATCH AUTOSEL 6.18-6.12] Bluetooth: btusb: MT7922: Add VID/PID 0489/e170
Sasha Levin
sashal at kernel.org
Mon Dec 8 16:15:09 PST 2025
From: Chris Lu <chris.lu at 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 at mediatek.com>
Reviewed-by: Paul Menzel <pmenzel at molgen.mpg.de>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz at intel.com>
Signed-off-by: Sasha Levin <sashal at 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 at 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
More information about the linux-arm-kernel
mailing list