From: WangYuli wangyuli@uniontech.com
[ Upstream commit c4dbb1bdada90168dd5fa2f7e4553cb0e1dad3c8 ]
The information in /sys/kernel/debug/usb/devices about the Bluetooth device is listed as the below:
T: Bus=01 Lev=01 Prnt=01 Port=01 Cnt=02 Dev#= 3 Spd=12 MxCh= 0 D: Ver= 1.00 Cls=e0(wlcon) Sub=01 Prot=01 MxPS=64 #Cfgs= 1 P: Vendor=0bda ProdID=b850 Rev= 0.00 S: Manufacturer=Realtek S: Product=Bluetooth Radio S: SerialNumber=00e04c000001 C:* #Ifs= 2 Cfg#= 1 Atr=e0 MxPwr=500mA 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=1ms E: Ad=02(O) Atr=02(Bulk) MxPS= 64 Ivl=0ms E: Ad=82(I) Atr=02(Bulk) MxPS= 64 Ivl=0ms I:* If#= 1 Alt= 0 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb E: Ad=03(O) Atr=01(Isoc) MxPS= 0 Ivl=1ms E: Ad=83(I) 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=03(O) Atr=01(Isoc) MxPS= 9 Ivl=1ms E: Ad=83(I) 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=03(O) Atr=01(Isoc) MxPS= 17 Ivl=1ms E: Ad=83(I) 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=03(O) Atr=01(Isoc) MxPS= 25 Ivl=1ms E: Ad=83(I) 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=03(O) Atr=01(Isoc) MxPS= 33 Ivl=1ms E: Ad=83(I) 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=03(O) Atr=01(Isoc) MxPS= 49 Ivl=1ms E: Ad=83(I) 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=03(O) Atr=01(Isoc) MxPS= 63 Ivl=1ms E: Ad=83(I) Atr=01(Isoc) MxPS= 63 Ivl=1ms
Co-developed-by: Hao Li lihao1@uniontech.com Signed-off-by: Hao Li lihao1@uniontech.com Signed-off-by: WangYuli wangyuli@uniontech.com Signed-off-by: Luiz Augusto von Dentz luiz.von.dentz@intel.com Signed-off-by: Sasha Levin sashal@kernel.org ---
Now let me analyze this commit thoroughly based on the criteria and compare it with the similar historical commits. **YES** This commit should be backported to stable kernel trees. **Extensive Analysis:** **1. Nature of the Change:** The commit adds USB device ID support for a new Realtek RTL8851BE Bluetooth device (0x0bda:0xb850) to the `quirks_table` in `drivers/bluetooth/btusb.c`. This is a minimal, contained change that adds exactly one line: ```c { USB_DEVICE(0x0bda, 0xb850), .driver_info = BTUSB_REALTEK }, ``` **2. Comparison with Historical Similar Commits:** All provided historical similar commits (commits #2-#5) that add Realtek Bluetooth device IDs have "Backport Status: YES". These commits follow the exact same pattern: - Adding USB device IDs for Realtek Bluetooth chips - Minimal code changes (single line additions to the device table) - Similar commit message structure with device information from `/sys/kernel/debug/usb/devices` - Same driver_info flags (BTUSB_REALTEK and sometimes BTUSB_WIDEBAND_SPEECH) The only commit marked with "Backport Status: NO" (commit #1) was for RTL8851BE device 13d3:3600, but this appears to be an inconsistent marking since it's functionally identical to the others. **3. Bug Fix Criteria:** This commit fixes a real user issue - users with this specific RTL8851BE device variant would not have working Bluetooth functionality without this device ID entry. The fix enables hardware that was previously non-functional. **4. Risk Assessment:** The risk is extremely minimal because: - It only adds a device ID to an existing, well-tested code path - The BTUSB_REALTEK flag directs the device to established Realtek-specific handling code - No existing functionality is modified - The change is confined to the device recognition table **5. Code Context Analysis:** Examining the actual kernel code at `/home/sasha/linux/drivers/bluetooth/btusb.c:516`, I can confirm the commit has been applied and fits perfectly within the existing RTL8851BE device section. The device is grouped appropriately with other RTL8851BE devices and uses the same driver_info flags as the existing RTL8851BE entry (0x13d3:0x3600). **6. Stable Tree Compatibility:** Device ID additions like this are ideal for stable tree backporting because they: - Fix hardware compatibility issues for specific devices - Don't introduce new features or architectural changes - Follow the stable kernel rule of "important fixes with minimal risk" - Are self-contained and don't depend on other changes **7. User Impact:** Without this change, users with RTL8851BE devices using vendor ID 0x0bda and product ID 0xb850 would have non-functional Bluetooth, which significantly impacts user experience. The commit perfectly matches the pattern of previously approved similar commits and meets all stable tree criteria for backporting.
drivers/bluetooth/btusb.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c index c7c3cd0dcd49e..ef9689f877691 100644 --- a/drivers/bluetooth/btusb.c +++ b/drivers/bluetooth/btusb.c @@ -513,6 +513,7 @@ static const struct usb_device_id quirks_table[] = { BTUSB_WIDEBAND_SPEECH },
/* Realtek 8851BE Bluetooth devices */ + { USB_DEVICE(0x0bda, 0xb850), .driver_info = BTUSB_REALTEK }, { USB_DEVICE(0x13d3, 0x3600), .driver_info = BTUSB_REALTEK },
/* Realtek 8852AE Bluetooth devices */