I successfully added the files AthrBT_0x31010100.dfu and ramps_0x31010100_40.dfu to the initramfs:
$ man dracut.conf
...
install_items+=" <file> <file> ...] "
Specify additional files to include in the initramfs, separated by spaces.
...
# nano /etc/dracut.conf.d/01-bluetooth.conf
force_drivers+="ath3k btusb"
install_items+="/lib/firmware/ar3k/AthrBT_0x31010100.dfu /lib/firmware/ar3k/ramps_0x31010100_40.dfu"
# reboot
Now, it does not complain about missing files anymore, and it seems my Bluetooth adapter is correctly identified:
# dmesg | egrep -i 'ath|bluetooth|firm|hal|usb|wifi'
0.507083] ACPI: [Firmware Bug]: BIOS _OSI(Linux) query ignored
2.637889] ACPI: bus type USB registered
2.639206] usbcore: registered new interface driver usbfs
2.640424] usbcore: registered new interface driver hub
2.641676] usbcore: registered new device driver usb
2.643414] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
2.647881] ehci-pci 0000:00:1d.0: new USB bus registered, assigned bus number 1
2.670124] ehci-pci 0000:00:1d.0: USB 2.0 started, EHCI 1.00
2.670228] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002
2.670274] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
2.670320] usb usb1: Product: EHCI Host Controller
2.670353] usb usb1: Manufacturer: Linux 4.11.4-1.gcba98ee-default ehci_hcd
2.670399] usb usb1: SerialNumber: 0000:00:1d.0
2.670580] hub 1-0:1.0: USB hub found
2.671150] xhci_hcd 0000:00:14.0: new USB bus registered, assigned bus number 2
2.672493] usb usb2: New USB device found, idVendor=1d6b, idProduct=0002
2.672539] usb usb2: New USB device strings: Mfr=3, Product=2, SerialNumber=1
2.672585] usb usb2: Product: xHCI Host Controller
2.672618] usb usb2: Manufacturer: Linux 4.11.4-1.gcba98ee-default xhci-hcd
2.672664] usb usb2: SerialNumber: 0000:00:14.0
2.672846] hub 2-0:1.0: USB hub found
2.675907] xhci_hcd 0000:00:14.0: new USB bus registered, assigned bus number 3
2.676533] usb usb3: New USB device found, idVendor=1d6b, idProduct=0003
2.676578] usb usb3: New USB device strings: Mfr=3, Product=2, SerialNumber=1
2.676625] usb usb3: Product: xHCI Host Controller
2.676656] usb usb3: Manufacturer: Linux 4.11.4-1.gcba98ee-default xhci-hcd
2.676702] usb usb3: SerialNumber: 0000:00:14.0
2.676877] hub 3-0:1.0: USB hub found
2.678002] usb: port power management may be unreliable
3.002146] usb 1-1: new high-speed USB device number 2 using ehci-pci
** 3.002156] usb 2-5: new full-speed USB device number 2 using xhci_hcd**
** 3.143037] usb 2-5: New USB device found, idVendor=04ca, idProduct=3014**
** 3.143038] usb 2-5: New USB device strings: Mfr=0, Product=0, SerialNumber=0**
** 3.147120] Bluetooth: Core ver 2.22**
** 3.147139] Bluetooth: HCI device and connection manager initialized**
** 3.147141] Bluetooth: HCI socket layer initialized**
** 3.147143] Bluetooth: L2CAP socket layer initialized**
** 3.147147] Bluetooth: SCO socket layer initialized**
** 3.148116] usbcore: registered new interface driver btusb**
3.150432] usb 1-1: New USB device found, idVendor=8087, idProduct=8001
3.150433] usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
3.150586] hub 1-1:1.0: USB hub found
** 3.153192] usbcore: registered new interface driver ath3k**
3.262136] usb 2-7: new high-speed USB device number 3 using xhci_hcd
3.411404] usb 2-7: New USB device found, idVendor=1bcf, idProduct=2c81
3.411406] usb 2-7: New USB device strings: Mfr=1, Product=2, SerialNumber=0
3.411406] usb 2-7: Product: HD WebCam
3.411407] usb 2-7: Manufacturer: NC2141103M50708908LM05
3.530196] usb 2-8: new high-speed USB device number 4 using xhci_hcd
3.670580] usb 2-8: New USB device found, idVendor=0bda, idProduct=0129
3.670584] usb 2-8: New USB device strings: Mfr=1, Product=2, SerialNumber=3
3.670586] usb 2-8: Product: USB2.0-CRW
3.670588] usb 2-8: Manufacturer: Generic
3.670590] usb 2-8: SerialNumber: 20100201396000000
** 3.671308] usb 2-5: USB disconnect, device number 2**
3.675887] usbcore: registered new interface driver rtsx_usb
** 3.934183] usb 2-5: new full-speed USB device number 5 using xhci_hcd**
** 9.323353] usb 2-5: New USB device found, idVendor=04ca, idProduct=3014**
** 9.324077] usb 2-5: New USB device strings: Mfr=0, Product=0, SerialNumber=0**
** 14.476841] usb 2-5: USB disconnect, device number 5**
14.919635] ath: phy0: WB335 2-ANT card detected
14.923495] ath: phy0: Set BT/WLAN RX diversity capability
14.934042] ath: phy0: Enable LNA combining
14.936330] ath: phy0: ASPM enabled: 0x42
14.937453] ath: EEPROM regdomain: 0x6c
14.937454] ath: EEPROM indicates we should expect a direct regpair map
14.937455] ath: Country alpha2 being used: 00
14.937455] ath: Regpair used: 0x6c
15.108629] ieee80211 phy0: Atheros AR9565 Rev:2 mem=0xffffa29f41c00000, irq=19
17.131412] input: HD WebCam as /devices/pci0000:00/0000:00:14.0/usb2/2-7/2-7:1.0/input/input22
17.132859] usbcore: registered new interface driver uvcvideo
17.134202] USB Video Class driver (1.1.1)
27.872910] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
27.876028] Bluetooth: BNEP filters: protocol multicast
27.877987] Bluetooth: BNEP socket layer initialized
But I’m concerned about those lines:
3.671308] usb 2-5: USB disconnect, device number 2
...
14.476841] usb 2-5: USB disconnect, device number 5
During this boot, my Bluetooth adapter was disconnected twice!
Also, I’m not able to use it. GNOME says there is no Bluetooth found. Indeed, it is not listed by lsusb:
# lsusb
Bus 001 Device 002: ID 8087:8001 Intel Corp.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 002 Device 004: ID 0bda:0129 Realtek Semiconductor Corp. RTS5129 Card Reader Controller
Bus 002 Device 003: ID 1bcf:2c81 Sunplus Innovation Technology Inc.
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Do you have any idea on why that is happening? And/or what could I try next?