Long story short, the solution was to install the latest firmware. In this case, I have an Intel NUC8i7HVK Mini PC with Intel Wireless-AC 8265 and Bluetooth 4.2. I installed the Intel wireless firmware package from experimental:
apt -t experimental install firmware-iwlwifi
This is also running current experimental kernel:
# uname -a Linux nuc8i7hvk01 4.18.0-rc4-amd64 #1 SMP Debian 4.18~rc4-1~exp1 (2018-07-12) x86_64 GNU/Linux
Which provided a more recent load on boot:
[ 2.478527] iwlwifi 0000:06:00.0: firmware: direct-loading firmware iwlwifi-8265-36.ucode
Upon reboot, it was easy to scan, connect, and pair the Logitech MX Anywhere 2S mouse.
For future reference, here are some commands to see some activiites:
$ hcitool dev
Devices:
hci0 0C:54:15:66:3B:9E
$ hciconfig
hci0: Type: Primary Bus: USB
BD Address: 0C:54:15:66:3B:9E ACL MTU: 1021:4 SCO MTU: 96:6
UP RUNNING PSCAN ISCAN
RX bytes:41366 acl:2102 sco:0 events:164 errors:0
TX bytes:4913 acl:29 sco:0 commands:75 errors:0
# bluetoothctl Agent registered [MX Anywhere 2S]# help Menu main: Available commands: ------------------- advertise Advertise Options Submenu scan Scan Options Submenu gatt Generic Attribute Submenu list List available controllers show [ctrl] Controller information selectSelect default controller devices List available devices paired-devices List paired devices system-alias Set controller alias reset-alias Reset controller alias power Set controller power pairable Set controller pairable mode discoverable Set controller discoverable mode agent Enable/disable agent with given capability default-agent Set agent as the default one advertise Enable/disable advertising with given type set-alias Set device alias scan Scan for devices info [dev] Device information pair [dev] Pair with device trust [dev] Trust device untrust [dev] Untrust device block [dev] Block device unblock [dev] Unblock device remove Remove device connect Connect device disconnect [dev] Disconnect device menu Select submenu version Display version quit Quit program exit Quit program help Display help about this program
[MX Anywhere 2S]# paired-devices Device E1:38:CB:49:A9:A5 MX Anywhere 2S [MX Anywhere 2S]# devices Device E1:38:CB:49:A9:A5 MX Anywhere 2S [MX Anywhere 2S]# paired-devices Device E1:38:CB:49:A9:A5 MX Anywhere 2S
Debian wiki on bluetooth: Using Bluetooth in a Debian system
2024/06/02 If the mouse does not start when logging into KDE, the file '~/.config/bluedevilglobalrc' may need to be adjusted with:
[Adapters] <Your Bluetooth adapter> mac_powered=true
Even though you appear to enable it in the bluetooth configuration screen, it does not seem to 'stick'. Another 'fix' is after setting the powered option to true make the file read-only so that it doesn't get set to false again (should that happen).
