Firmware version not showing on dmesg. HP ProBook 6470b. Ubuntu 24.04. BCM20702A0.

[danbates2]

I'm looking to update the firmware with my onboard my BT device as sound quality is so poor, I've tried many other avenues.. The introductory README.md states a dmesg command used to find current firmware version. My system's not providing the expected output.

$ sudo dmesg | grep -i bluetooth

[    6.862113] Bluetooth: Core ver 2.22
[    6.862157] NET: Registered PF_BLUETOOTH protocol family
[    6.862160] Bluetooth: HCI device and connection manager initialized
[    6.862165] Bluetooth: HCI socket layer initialized
[    6.862168] Bluetooth: L2CAP socket layer initialized
[    6.862177] Bluetooth: SCO socket layer initialized
[    8.010732] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[    8.010739] Bluetooth: BNEP filters: protocol multicast
[    8.010745] Bluetooth: BNEP socket layer initialized
[    8.015707] Bluetooth: MGMT ver 1.22
[   10.895177] Bluetooth: RFCOMM TTY layer initialized
[   10.895189] Bluetooth: RFCOMM socket layer initialized
[   10.895199] Bluetooth: RFCOMM ver 1.11

My laptop is old.. BIOS settings are for UEFI Native mode and I'm running a fresh install of Ubuntu.

Of interest perhaps is a screenshot of the Firmware Updater app that's part of Ubuntu. This shows the Broadcom BT device and states it's updatable.