Dennis HilkLinux diagnosticsDE

Bluetooth

Realtek RTL8761BU-class USB Bluetooth

A Realtek USB family with a BU firmware route that differs from the UART B branch. The USB/UART distinction changes the expected filename.

Editorial source review: Share public profileOpen in the identification tool
On this page
  1. Overview & identity
  2. Driver & binding
  3. Firmware
  4. Read-only diagnostics
  5. Limitations & related issues
  6. References

Overview & identity

0bda:8771 appears in the 8761BUV USB group. btrtl still checks LMP subversion, HCI revision and transport before choosing a firmware entry.

Curated identifiers
usb 0bda:8771

A numeric match establishes a candidate family within the reviewed evidence. Marketing names, board variants, subsystem conditions and successful operation remain separate questions.

Driver & binding

btusb provides transport and btrtl supplies the Realtek setup helper. For a matching 8761BU controller the helper declares a BU firmware image and an optional configuration name.

  • btusb — kernel driver/module candidate
  • btrtl — kernel driver/module candidate

Detected, bound, operational: learn the difference

Firmware

Device/revision dependent

These names apply to the helper’s matched 8761BU USB entry. Its source marks configuration as optional; the product pair alone is not a ROM-version check.

Checked examples or filename branches, not a complete installation list:

  • rtl_bt/rtl8761bu_fw.bin
  • rtl_bt/rtl8761bu_config.bin

Inspect firmware packaging on your distribution

Read-only diagnostics

Run one displayed command at a time. Replace uppercase placeholders with the affected device, interface or module from your own output. Commands are never executed here. Read-only output can still contain private identifiers.

Read USB transport binding

lsusb -t

Find the controller’s port and interface in the USB tree. Driver=btusb is transport binding, not proof that firmware setup or audio profiles succeeded. This query normally needs no root privileges.

Read controllers visible to BlueZ

bluetoothctl list

This asks the BlueZ daemon for known controllers without discovery or pairing. An empty response can mean daemon or D-Bus access problems as well as absent controllers; compare kernel enumeration. Normally no root privileges are needed.

Read controller initialization

journalctl -k -b --no-pager

Read the current boot’s kernel messages for the controller, requested firmware and setup result. Journal visibility depends on local permissions; an unreadable log is not evidence of no errors. This command does not change the device.

Limitations & related issues

Do not replace rtl8761bu files with rtl8761b UART files because the names look similar. ROM/HCI details and actual setup success remain stronger evidence than the USB group label.

These guides are linked for relevant observations, not as known defects of every device in this family.

Choose a hardware diagnostic workflow · Inspect a log excerpt in Fix Lab

References

Source review records a checked implementation or document, not a reproduced hardware test. Version-specific tables do not establish a minimum kernel or guaranteed operation.