Can't get Asus BT400 Broadcom Bluetooth USB adapter to work on Fedora 34!

I purchased this Asus BT400 bluetooth adapter, and tried connecting to my desktop which uses this Asus motherboad. I am using Fedora 34:

$ cat /etc/fedora-release 
Fedora release 34 (Thirty Four)
$ uname -a
Linux DESKTOP-AQQDB51 5.13.12-200.fc34.x86_64 #1 SMP Wed Aug 18 13:27:18 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

When I first plugged the adapter in, I could pair it with a headset using bluetoothctl, but I couldn’t get any audio to output to the headset. I looked at the journalctl output, and I saw some messages that seemed to indicate a missing driver. In particular, these messages (which were highlight in red):

Aug 28 09:24:59 DESKTOP-AQQDB51 kernel: Bluetooth: hci0: BCM: 'brcm/BCM-0b05-17cb.hcd'
Aug 28 09:24:59 DESKTOP-AQQDB51 kernel: Bluetooth: hci0: BCM: 'brcm/BCM20702A1-0b05-17cb.hcd'
Aug 28 09:24:59 DESKTOP-AQQDB51 kernel: Bluetooth: hci0: BCM: firmware Patch file not found, tried:
Aug 28 09:24:59 DESKTOP-AQQDB51 kernel: Bluetooth: hci0: BCM20702A1 (001.002.014) build 0000
Aug 28 09:24:59 DESKTOP-AQQDB51 kernel: Bluetooth: hci0: BlueZ 5.61
Aug 28 09:24:59 DESKTOP-AQQDB51 kernel: Bluetooth: hci0: BCM: features 0x07
Aug 28 09:24:59 DESKTOP-AQQDB51 kernel: Bluetooth: hci0: BCM: chip id 63

I did some searching, found this article, and followed the instructions to install the correct driver. After copying the BCM20702A1-0b05-17cb.hcd file to /lib/firmware/brcm/ and rebooting the workstation, the error messages about the “firmware Patch file” went away. However, I still couldn’t get the audio to play through the headset. Looking at journalctl again, I now see the following:

This series of messages happens over and over, as long as the USB dongle is connected. At this point, I am stumped. Has anyone run into this before? Any suggestions?

We need to know exactly what chipset is used to be able to match the proper driver, so please post the output of “lspci -v” and “lsusb”.

$ lspci -v
00:00.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Starship/Matisse Root Complex
	Subsystem: ASUSTeK Computer Inc. Device 87c0
	Flags: fast devsel

00:00.2 IOMMU: Advanced Micro Devices, Inc. [AMD] Starship/Matisse IOMMU
	Subsystem: ASUSTeK Computer Inc. Device 87c0
	Flags: fast devsel, IRQ 25
	Capabilities: <access denied>

00:01.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Starship/Matisse PCIe Dummy Host Bridge
	Flags: fast devsel, IOMMU group 0

00:01.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Starship/Matisse GPP Bridge (prog-if 00 [Normal decode])
	Flags: bus master, fast devsel, latency 0, IRQ 26, IOMMU group 1
	Bus: primary=00, secondary=01, subordinate=01, sec-latency=0
	I/O behind bridge: [disabled]
	Memory behind bridge: fc800000-fc8fffff [size=1M]
	Prefetchable memory behind bridge: [disabled]
	Capabilities: <access denied>
	Kernel driver in use: pcieport

00:01.2 PCI bridge: Advanced Micro Devices, Inc. [AMD] Starship/Matisse GPP Bridge (prog-if 00 [Normal decode])
	Flags: bus master, fast devsel, latency 0, IRQ 27, IOMMU group 2
	Bus: primary=00, secondary=02, subordinate=07, sec-latency=0
	I/O behind bridge: 0000f000-0000ffff [size=4K]
	Memory behind bridge: fc500000-fc7fffff [size=3M]
	Prefetchable memory behind bridge: [disabled]
	Capabilities: <access denied>
	Kernel driver in use: pcieport

00:02.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Starship/Matisse PCIe Dummy Host Bridge
	DeviceName:  Onboard IGD
	Flags: fast devsel, IOMMU group 3

00:03.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Starship/Matisse PCIe Dummy Host Bridge
	Flags: fast devsel, IOMMU group 4

00:03.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Starship/Matisse GPP Bridge (prog-if 00 [Normal decode])
	Flags: bus master, fast devsel, latency 0, IRQ 28, IOMMU group 5
	Bus: primary=00, secondary=08, subordinate=08, sec-latency=0
	I/O behind bridge: 0000e000-0000efff [size=4K]
	Memory behind bridge: fb000000-fc0fffff [size=17M]
	Prefetchable memory behind bridge: 00000000e0000000-00000000e9ffffff [size=160M]
	Capabilities: <access denied>
	Kernel driver in use: pcieport

00:04.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Starship/Matisse PCIe Dummy Host Bridge
	Flags: fast devsel, IOMMU group 6

00:05.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Starship/Matisse PCIe Dummy Host Bridge
	Flags: fast devsel, IOMMU group 7

00:07.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Starship/Matisse PCIe Dummy Host Bridge
	Flags: fast devsel, IOMMU group 8

00:07.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Starship/Matisse Internal PCIe GPP Bridge 0 to bus[E:B] (prog-if 00 [Normal decode])
	Flags: bus master, fast devsel, latency 0, IRQ 30, IOMMU group 9
	Bus: primary=00, secondary=09, subordinate=09, sec-latency=0
	I/O behind bridge: [disabled]
	Memory behind bridge: [disabled]
	Prefetchable memory behind bridge: [disabled]
	Capabilities: <access denied>
	Kernel driver in use: pcieport

00:08.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Starship/Matisse PCIe Dummy Host Bridge
	Flags: fast devsel, IOMMU group 10

00:08.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Starship/Matisse Internal PCIe GPP Bridge 0 to bus[E:B] (prog-if 00 [Normal decode])
	Flags: bus master, fast devsel, latency 0, IRQ 31, IOMMU group 11
	Bus: primary=00, secondary=0a, subordinate=0a, sec-latency=0
	I/O behind bridge: [disabled]
	Memory behind bridge: fc200000-fc4fffff [size=3M]
	Prefetchable memory behind bridge: [disabled]
	Capabilities: <access denied>
	Kernel driver in use: pcieport

00:14.0 SMBus: Advanced Micro Devices, Inc. [AMD] FCH SMBus Controller (rev 61)
	Subsystem: ASUSTeK Computer Inc. Device 87c0
	Flags: 66MHz, medium devsel, IOMMU group 12
	Kernel driver in use: piix4_smbus
	Kernel modules: i2c_piix4, sp5100_tco

00:14.3 ISA bridge: Advanced Micro Devices, Inc. [AMD] FCH LPC Bridge (rev 51)
	Subsystem: ASUSTeK Computer Inc. Device 87c0
	Flags: bus master, 66MHz, medium devsel, latency 0, IOMMU group 12

00:18.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Matisse Device 24: Function 0
	Flags: fast devsel, IOMMU group 13

00:18.1 Host bridge: Advanced Micro Devices, Inc. [AMD] Matisse Device 24: Function 1
	Flags: fast devsel, IOMMU group 13

00:18.2 Host bridge: Advanced Micro Devices, Inc. [AMD] Matisse Device 24: Function 2
	Flags: fast devsel, IOMMU group 13

00:18.3 Host bridge: Advanced Micro Devices, Inc. [AMD] Matisse Device 24: Function 3
	Flags: fast devsel, IOMMU group 13
	Kernel driver in use: k10temp
	Kernel modules: k10temp

00:18.4 Host bridge: Advanced Micro Devices, Inc. [AMD] Matisse Device 24: Function 4
	Flags: fast devsel, IOMMU group 13

00:18.5 Host bridge: Advanced Micro Devices, Inc. [AMD] Matisse Device 24: Function 5
	Flags: fast devsel, IOMMU group 13

00:18.6 Host bridge: Advanced Micro Devices, Inc. [AMD] Matisse Device 24: Function 6
	Flags: fast devsel, IOMMU group 13

00:18.7 Host bridge: Advanced Micro Devices, Inc. [AMD] Matisse Device 24: Function 7
	Flags: fast devsel, IOMMU group 13

01:00.0 Non-Volatile memory controller: Micron/Crucial Technology Device 5403 (rev 03) (prog-if 02 [NVM Express])
	Subsystem: Micron/Crucial Technology Device 1100
	Flags: bus master, fast devsel, latency 0, IRQ 54, NUMA node 0, IOMMU group 14
	Memory at fc800000 (64-bit, non-prefetchable) [size=16K]
	Capabilities: <access denied>
	Kernel driver in use: nvme
	Kernel modules: nvme

02:00.0 USB controller: Advanced Micro Devices, Inc. [AMD] Device 43ee (prog-if 30 [XHCI])
	Subsystem: ASMedia Technology Inc. Device 1142
	Flags: bus master, fast devsel, latency 0, IRQ 41, IOMMU group 15
	Memory at fc7a0000 (64-bit, non-prefetchable) [size=32K]
	Capabilities: <access denied>
	Kernel driver in use: xhci_hcd

02:00.1 SATA controller: Advanced Micro Devices, Inc. [AMD] Device 43eb (prog-if 01 [AHCI 1.0])
	Subsystem: ASMedia Technology Inc. Device 1062
	Flags: bus master, fast devsel, latency 0, IRQ 40, IOMMU group 15
	Memory at fc780000 (32-bit, non-prefetchable) [size=128K]
	Expansion ROM at fc700000 [disabled] [size=512K]
	Capabilities: <access denied>
	Kernel driver in use: ahci

02:00.2 PCI bridge: Advanced Micro Devices, Inc. [AMD] Device 43e9 (prog-if 00 [Normal decode])
	Flags: bus master, fast devsel, latency 0, IRQ 33, IOMMU group 15
	Bus: primary=02, secondary=03, subordinate=07, sec-latency=0
	I/O behind bridge: 0000f000-0000ffff [size=4K]
	Memory behind bridge: fc500000-fc6fffff [size=2M]
	Prefetchable memory behind bridge: [disabled]
	Capabilities: <access denied>
	Kernel driver in use: pcieport

03:00.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] Device 43ea (prog-if 00 [Normal decode])
	Flags: bus master, fast devsel, latency 0, IRQ 35, IOMMU group 15
	Bus: primary=03, secondary=04, subordinate=04, sec-latency=0
	I/O behind bridge: [disabled]
	Memory behind bridge: [disabled]
	Prefetchable memory behind bridge: [disabled]
	Capabilities: <access denied>
	Kernel driver in use: pcieport

03:04.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] Device 43ea (prog-if 00 [Normal decode])
	Flags: bus master, fast devsel, latency 0, IRQ 36, IOMMU group 15
	Bus: primary=03, secondary=05, subordinate=05, sec-latency=0
	I/O behind bridge: [disabled]
	Memory behind bridge: fc600000-fc6fffff [size=1M]
	Prefetchable memory behind bridge: [disabled]
	Capabilities: <access denied>
	Kernel driver in use: pcieport

03:08.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] Device 43ea (prog-if 00 [Normal decode])
	Flags: bus master, fast devsel, latency 0, IRQ 37, IOMMU group 15
	Bus: primary=03, secondary=06, subordinate=06, sec-latency=0
	I/O behind bridge: [disabled]
	Memory behind bridge: [disabled]
	Prefetchable memory behind bridge: [disabled]
	Capabilities: <access denied>
	Kernel driver in use: pcieport

03:09.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] Device 43ea (prog-if 00 [Normal decode])
	Flags: bus master, fast devsel, latency 0, IRQ 39, IOMMU group 15
	Bus: primary=03, secondary=07, subordinate=07, sec-latency=0
	I/O behind bridge: 0000f000-0000ffff [size=4K]
	Memory behind bridge: fc500000-fc5fffff [size=1M]
	Prefetchable memory behind bridge: [disabled]
	Capabilities: <access denied>
	Kernel driver in use: pcieport

05:00.0 Non-Volatile memory controller: Sandisk Corp WD Black SN750 / PC SN730 NVMe SSD (prog-if 02 [NVM Express])
	Subsystem: Sandisk Corp WD Black SN750 / PC SN730 NVMe SSD
	Flags: bus master, fast devsel, latency 0, IRQ 34, NUMA node 0, IOMMU group 15
	Memory at fc600000 (64-bit, non-prefetchable) [size=16K]
	Memory at fc604000 (64-bit, non-prefetchable) [size=256]
	Capabilities: <access denied>
	Kernel driver in use: nvme
	Kernel modules: nvme

07:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8125 2.5GbE Controller (rev 04)
	Subsystem: ASUSTeK Computer Inc. Device 87d7
	Flags: bus master, fast devsel, latency 0, IRQ 38, IOMMU group 15
	I/O ports at f000 [size=256]
	Memory at fc500000 (64-bit, non-prefetchable) [size=64K]
	Memory at fc510000 (64-bit, non-prefetchable) [size=16K]
	Capabilities: <access denied>
	Kernel driver in use: r8169
	Kernel modules: r8169

08:00.0 VGA compatible controller: NVIDIA Corporation GK208B [GeForce GT 710] (rev a1) (prog-if 00 [VGA controller])
	Subsystem: Micro-Star International Co., Ltd. [MSI] Device 8c93
	Flags: bus master, fast devsel, latency 0, IRQ 106, IOMMU group 16
	Memory at fb000000 (32-bit, non-prefetchable) [size=16M]
	Memory at e0000000 (64-bit, prefetchable) [size=128M]
	Memory at e8000000 (64-bit, prefetchable) [size=32M]
	I/O ports at e000 [size=128]
	Expansion ROM at 000c0000 [disabled] [size=128K]
	Capabilities: <access denied>
	Kernel driver in use: nouveau
	Kernel modules: nouveau

08:00.1 Audio device: NVIDIA Corporation GK208 HDMI/DP Audio Controller (rev a1)
	Subsystem: Micro-Star International Co., Ltd. [MSI] Device 8c93
	Flags: bus master, fast devsel, latency 0, IRQ 107, IOMMU group 16
	Memory at fc080000 (32-bit, non-prefetchable) [size=16K]
	Capabilities: <access denied>
	Kernel driver in use: snd_hda_intel
	Kernel modules: snd_hda_intel

09:00.0 Non-Essential Instrumentation [1300]: Advanced Micro Devices, Inc. [AMD] Starship/Matisse PCIe Dummy Function
	Subsystem: ASUSTeK Computer Inc. Device 87c0
	Flags: fast devsel, IOMMU group 17
	Capabilities: <access denied>

0a:00.0 Non-Essential Instrumentation [1300]: Advanced Micro Devices, Inc. [AMD] Starship/Matisse Reserved SPP
	Subsystem: ASUSTeK Computer Inc. Device 87c0
	Flags: fast devsel, IOMMU group 18
	Capabilities: <access denied>

0a:00.1 Encryption controller: Advanced Micro Devices, Inc. [AMD] Starship/Matisse Cryptographic Coprocessor PSPCPP
	Subsystem: ASUSTeK Computer Inc. Device 87c0
	Flags: bus master, fast devsel, latency 0, IRQ 51, IOMMU group 19
	Memory at fc300000 (32-bit, non-prefetchable) [size=1M]
	Memory at fc408000 (32-bit, non-prefetchable) [size=8K]
	Capabilities: <access denied>
	Kernel driver in use: ccp
	Kernel modules: ccp

0a:00.3 USB controller: Advanced Micro Devices, Inc. [AMD] Matisse USB 3.0 Host Controller (prog-if 30 [XHCI])
	Subsystem: ASUSTeK Computer Inc. Device 87c0
	Flags: bus master, fast devsel, latency 0, IRQ 42, IOMMU group 20
	Memory at fc200000 (64-bit, non-prefetchable) [size=1M]
	Capabilities: <access denied>
	Kernel driver in use: xhci_hcd

0a:00.4 Audio device: Advanced Micro Devices, Inc. [AMD] Starship/Matisse HD Audio Controller
	Subsystem: ASUSTeK Computer Inc. Device 8797
	Flags: bus master, fast devsel, latency 0, IRQ 55, IOMMU group 21
	Memory at fc400000 (32-bit, non-prefetchable) [size=32K]
	Capabilities: <access denied>
	Kernel driver in use: snd_hda_intel
	Kernel modules: snd_hda_intel

$ lsusb -tv
/:  Bus 04.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 10000M
    ID 1d6b:0003 Linux Foundation 3.0 root hub
/:  Bus 03.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 480M
    ID 1d6b:0002 Linux Foundation 2.0 root hub
/:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 10000M
    ID 1d6b:0003 Linux Foundation 3.0 root hub
    |__ Port 4: Dev 2, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
        ID 21c4:0cd1  
/:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/10p, 480M
    ID 1d6b:0002 Linux Foundation 2.0 root hub
    |__ Port 3: Dev 2, If 2, Class=Chip/SmartCard, Driver=usbfs, 12M
        ID 1050:0407 Yubico.com Yubikey 4/5 OTP+U2F+CCID
    |__ Port 3: Dev 2, If 0, Class=Human Interface Device, Driver=usbhid, 12M
        ID 1050:0407 Yubico.com Yubikey 4/5 OTP+U2F+CCID
    |__ Port 3: Dev 2, If 1, Class=Human Interface Device, Driver=usbhid, 12M
        ID 1050:0407 Yubico.com Yubikey 4/5 OTP+U2F+CCID
    |__ Port 6: Dev 3, If 2, Class=Human Interface Device, Driver=usbhid, 12M
        ID 0b05:1939 ASUSTek Computer, Inc. 
    |__ Port 6: Dev 3, If 0, Class=Vendor Specific Class, Driver=, 12M
        ID 0b05:1939 ASUSTek Computer, Inc. 
    |__ Port 7: Dev 4, If 0, Class=Hub, Driver=hub/4p, 480M
        ID 05e3:0610 Genesys Logic, Inc. Hub
        |__ Port 4: Dev 33, If 3, Class=Application Specific Interface, Driver=, 12M
            ID 0b05:17cb ASUSTek Computer, Inc. Broadcom BCM20702A0 Bluetooth
        |__ Port 4: Dev 33, If 1, Class=Vendor Specific Class, Driver=btusb, 12M
            ID 0b05:17cb ASUSTek Computer, Inc. Broadcom BCM20702A0 Bluetooth
        |__ Port 4: Dev 33, If 2, Class=Vendor Specific Class, Driver=btusb, 12M
            ID 0b05:17cb ASUSTek Computer, Inc. Broadcom BCM20702A0 Bluetooth
        |__ Port 4: Dev 33, If 0, Class=Vendor Specific Class, Driver=btusb, 12M
            ID 0b05:17cb ASUSTek Computer, Inc. Broadcom BCM20702A0 Bluetooth
    |__ Port 9: Dev 5, If 0, Class=Hub, Driver=hub/4p, 480M
        ID 1a40:0101 Terminus Technology Inc. Hub
        |__ Port 3: Dev 7, If 2, Class=Human Interface Device, Driver=usbhid, 12M
            ID 1532:0096 Razer USA, Ltd 
        |__ Port 3: Dev 7, If 0, Class=Human Interface Device, Driver=usbhid, 12M
            ID 1532:0096 Razer USA, Ltd 
        |__ Port 3: Dev 7, If 3, Class=Human Interface Device, Driver=usbhid, 12M
            ID 1532:0096 Razer USA, Ltd 
        |__ Port 3: Dev 7, If 1, Class=Human Interface Device, Driver=usbhid, 12M
            ID 1532:0096 Razer USA, Ltd 
        |__ Port 4: Dev 8, If 0, Class=Human Interface Device, Driver=usbhid, 12M
            ID 0c45:767d Microdia 
        |__ Port 4: Dev 8, If 1, Class=Human Interface Device, Driver=usbhid, 12M