[PATCH] Bluetooth: btusb: Add USB ID 13d3:3556 for RTL8821CE

[PATCH] Bluetooth: btusb: Add USB ID 13d3:3556 for RTL8821CE

[Aritra Das]

The onboard Realtek RTL8821CE combo card on the ASUS PRIME B550-PLUS
AC-HES presents its Bluetooth function as USB ID 13d3:3556. This ID is
missing from quirks_table, so btusb matches the device only through the
generic Bluetooth class entry in btusb_table and driver_info stays zero.
BTUSB_REALTEK is therefore never set, btrtl never runs, and the
controller keeps executing its on-chip ROM firmware instead of loading
rtl_bt/rtl8821c_fw.bin and rtl_bt/rtl8821c_config.bin.

In that state BLE HID peripherals are unusable. A HHKB Hybrid keyboard
pairs and enumerates as a HID device, then the link drops within 10-30
seconds, repeatedly. The same keyboard is stable on the same host under
other operating systems.

Adding the ID lets btusb run the Realtek setup path:

  Bluetooth: hci0: RTL: examining hci_ver=08 hci_rev=000c lmp_ver=08 lmp_subver=8821
  Bluetooth: hci0: RTL: rom_version status=0 version=1
  Bluetooth: hci0: RTL: loading rtl_bt/rtl8821c_fw.bin
  Bluetooth: hci0: RTL: loading rtl_bt/rtl8821c_config.bin
  Bluetooth: hci0: RTL: cfg_sz 10, total sz 34926
  Bluetooth: hci0: RTL: fw version 0x75b8f098

With the firmware loaded the same keyboard has stayed connected for over
11 hours without a single drop.

Device descriptor:

T:  Bus=01 Lev=01 Prnt=01 Port=04 Cnt=02 Dev#=  2 Spd=12   MxCh= 0
D:  Ver= 1.10 Cls=e0(wlcon) Sub=01 Prot=01 MxPS=64 #Cfgs=  1
P:  Vendor=13d3 ProdID=3556 Rev=01.10
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=02(O) Atr=02(Bulk) MxPS=  64 Ivl=0ms
E:  Ad=81(I) Atr=03(Int.) MxPS=  16 Ivl=1ms
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

Signed-off-by: Aritra Das <aritra.rohit2003@gmail.com>
---
 drivers/bluetooth/btusb.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 03039ce..0424898 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -511,6 +511,8 @@ static const struct usb_device_id quirks_table[] = {
 						     BTUSB_WIDEBAND_SPEECH },
 	{ USB_DEVICE(0x13d3, 0x3533), .driver_info = BTUSB_REALTEK |
 						     BTUSB_WIDEBAND_SPEECH },
+	{ USB_DEVICE(0x13d3, 0x3556), .driver_info = BTUSB_REALTEK |
+						     BTUSB_WIDEBAND_SPEECH },
 	{ USB_DEVICE(0x13d3, 0x3558), .driver_info = BTUSB_REALTEK |
 						     BTUSB_WIDEBAND_SPEECH },
 
base-commit: 6696072ffe07205255cf83621a95a1aa2f9f6e62

RE: Bluetooth: btusb: Add USB ID 13d3:3556 for RTL8821CE

[bluez.test.bot]

[-- Attachment #1: Type: text/plain, Size: 2341 bytes --]

This is automated email and please do not reply to this email!

Dear submitter,

Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=1157292

---Test result---

Test Summary:
CheckPatch                    FAIL      0.77 seconds
VerifyFixes                   PASS      0.14 seconds
VerifySignedoff               PASS      0.14 seconds
GitLint                       FAIL      0.34 seconds
SubjectPrefix                 PASS      0.14 seconds
BuildKernel                   PASS      26.91 seconds
CheckAllWarning               PASS      29.31 seconds
CheckSparse                   PASS      28.62 seconds
BuildKernel32                 PASS      25.88 seconds
CheckKernelLLVM               SKIP      0.00 seconds
TestRunnerSetup               PASS      475.44 seconds
IncrementalBuild              PASS      25.71 seconds

Details
##############################
Test: CheckPatch - FAIL
Desc: Run checkpatch.pl script
Output:
Bluetooth: btusb: Add USB ID 13d3:3556 for RTL8821CE
WARNING: Prefer a maximum 75 chars per line (possible unwrapped commit description?)
#112: 
  Bluetooth: hci0: RTL: examining hci_ver=08 hci_rev=000c lmp_ver=08 lmp_subver=8821

total: 0 errors, 1 warnings, 8 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
      mechanically convert to the typical style using --fix or --fix-inplace.

/github/workspace/src/patch/14788283.patch has style problems, please review.

NOTE: Ignored message types: UNKNOWN_COMMIT_ID

NOTE: If any of the errors are false positives, please report
      them to the maintainer, see CHECKPATCH in MAINTAINERS.


##############################
Test: GitLint - FAIL
Desc: Run gitlint
Output:
Bluetooth: btusb: Add USB ID 13d3:3556 for RTL8821CE

18: B1 Line exceeds max length (84>80): "  Bluetooth: hci0: RTL: examining hci_ver=08 hci_rev=000c lmp_ver=08 lmp_subver=8821"
33: B2 Line has trailing whitespace: "S:  Manufacturer=Realtek "
34: B2 Line has trailing whitespace: "S:  Product=Bluetooth Radio "
##############################
Test: CheckKernelLLVM - SKIP
Desc: Build kernel with LLVM + context analysis
Output:
Clang not found


https://github.com/bluez/bluetooth-next/pull/698

---
Regards,
Linux Bluetooth

Re: [PATCH] Bluetooth: btusb: Add USB ID 13d3:3556 for RTL8821CE

[patchwork-bot+bluetooth]

Hello:

This patch was applied to bluetooth/bluetooth-next.git (master)
by Luiz Augusto von Dentz <luiz.von.dentz@intel.com>:

On Thu,  3 Sep 2026 10:03:22 -0700 you wrote:
> The onboard Realtek RTL8821CE combo card on the ASUS PRIME B550-PLUS
> AC-HES presents its Bluetooth function as USB ID 13d3:3556. This ID is
> missing from quirks_table, so btusb matches the device only through the
> generic Bluetooth class entry in btusb_table and driver_info stays zero.
> BTUSB_REALTEK is therefore never set, btrtl never runs, and the
> controller keeps executing its on-chip ROM firmware instead of loading
> rtl_bt/rtl8821c_fw.bin and rtl_bt/rtl8821c_config.bin.
> 
> [...]

Here is the summary with links:
  - Bluetooth: btusb: Add USB ID 13d3:3556 for RTL8821CE
    https://git.kernel.org/bluetooth/bluetooth-next/c/88a6bc5607e2

You are awesome, thank you!
-- 
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