usb 1-1: new full-speed USB device number 4 using dwc_otg usb 1-1: Product: JQ-BT100 bluetooth: hci0: request failed: -110 Alex recognized the pattern — the kernel didn’t have the right firmware or driver for the jq-bt series. Jasmine checked the module’s datasheet: Chip: JQ-BT v3.2 Host interface: UART / USB Driver: jq-bt.ko (custom for Linux kernel 5.10+) Firmware: jq_bt_fw.bin The driver wasn’t in the mainline kernel. The vendor provided a tarball with source code and a README:
dmesg showed:
jq-bt: loading firmware jq_bt_fw.bin failed (err -2) jq-bt: device hci0: initialization timeout The firmware file was missing. Jasmine found it on the vendor’s FTP site under /lib/firmware/ but incorrectly named jq-bt-fw.bin instead of jq_bt_fw.bin . Alex symlinked it: jq-bt bluetooth driver