Package: linux-image-7.2.9+deb13-amd64 Version: 7.2.9-1~bpo13+1 Severity: important Tags: upstream
Dear Debian Kernel Team, I would like to report a reproducible Bluetooth regression affecting the Realtek RTL8761BU USB Bluetooth adapter (USB ID 0bda) on Debian 13 (Trixie) with the Linux 7.2.9 kernel from trixie-backports. Hardware and software environment - Host: nyrok-pc-lnx - Distribution: Debian GNU/Linux 13 - Affected kernel: 7.2.9+deb13-amd64 - Affected package: 7.2.9-1~bpo13+1 - Working kernel: 6.12.113+deb13-amd64 - BlueZ: 5.82-1.1 - Bluetooth adapter: Realtek RTL8761BU, USB 0bda - Firmware: rtl_bt/rtl8761bu_fw.bin - Firmware version: 0xdfc6d922 - Bluetooth peripheral: Logitech MX Mechanical, Bluetooth LE HID (046d) - Connection topology: USB adapter directly connected to xHCI root hub Observed behavior On Linux 7.2.9, the Bluetooth controller intermittently stops responding. Following a system reboot, the Logitech MX Mechanical keyboard may fail to reconnect automatically. Restarting the Bluetooth service temporarily restores normal operation. The following errors were recorded in the kernel log on October 23, 2026: Bluetooth: hci0: command 0x200c tx timeout Bluetooth: hci0: Resetting usb device. Bluetooth: hci0: Opcode 0x200c failed: -110 Bluetooth: hci0: Unable to disable scanning: -110 Bluetooth: hci0: Error when powering off device on rfkill (-110) After the reset, the adapter reinitializes as hci1, reloads the same Realtek firmware, and the Logitech keyboard reconnects. Regression confirmation I installed and booted Debian’s 6.12.113 kernel on the same machine, using the same Bluetooth adapter and keyboard. The issue does not reproduce with Linux 6.12.113. No Bluetooth pairing changes or hardware replacement were necessary. Upstream investigation and proposed fix This behavior closely matches the known RTL8761BU regression associated with HCI_QUIRK_BROKEN_EXT_SCAN. The following upstream fix appears directly applicable: Bluetooth: btusb: drop BROKEN_EXT_SCAN quirk for 0bda Commit: fdd5964bd389936856971647fcac3442117009dc https://git.kernel.org/bluetooth/bluetooth-next/c/fdd5964bd389 The patch was accepted into bluetooth-next on September 29, 2026. A closely matching regression, including the same USB ID, firmware version and HCI timeout, is documented here: https://github.com/pop-os/pop/issues/4135 Request Could the Debian Kernel Team consider backporting the upstream fix to the Linux 7.2 packages used by trixie-backports, or confirm which upcoming Debian kernel package will include the correction? I can provide additional kernel logs and test a patched kernel or btusb module if necessary. Thank you for maintaining the Debian kernel packages.
