Apple bluetooth USB driver is 100% busy despite BT switched off

[Norse]

Just upgraded from 17.04 to 17.10 on a 2011 macbook air.
Battery drain is markedly more severe.
Looking at powertop, the main difference is that the Apple USB Bluetooth driver is drawing ~2.5W and is showing as 100% busy.
Bluetooth is switched off.
I have tried rfkill, blacklisting btusb, modifying the /etc/bluetooth/main.conf to not autoenable and to set InitiallyPowered to false.
None of these work.

powertop output:

 2.58 W 100.0% Device USB device: Bluetooth USB Host Controller (Apple Inc.)

ProblemType: Bug
DistroRelease: Ubuntu 17.10
Package: bluetooth (not installed)
ProcVersionSignature: Ubuntu 4.13.0-16.19-generic 4.13.4
Uname: Linux 4.13.0-16-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.20.7-0ubuntu3
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Sun Oct 15 11:45:16 2017
InstallationDate: Installed on 2014-11-09 (1070 days ago)
InstallationMedia: Ubuntu 14.10 "Utopic Unicorn" - Release amd64 (20141022.1)
InterestingModules: bluetooth
MachineType: Apple Inc. MacBookAir4,2
ProcEnviron:
 LANG=en_US.UTF-8
 TERM=xterm-256color
 SHELL=/bin/bash
 XDG_RUNTIME_DIR=<set>
 PATH=(custom, user)
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.13.0-16-generic.efi.signed root=UUID=58091989-ee9b-4c99-afa8-fffa56a1f3af ro quiet splash crashkernel=384M-:128M vt.handoff=7
SourcePackage: bluez
UpgradeStatus: Upgraded to artful on 2017-10-15 (0 days ago)
dmi.bios.date: 06/08/2015
dmi.bios.vendor: Apple Inc.
dmi.bios.version: MBA41.88Z.0077.B12.1506081728
dmi.board.asset.tag: Base Board Asset Tag#
dmi.board.name: Mac-742912EFDBEE19B3
dmi.board.vendor: Apple Inc.
dmi.board.version: MacBookAir4,2
dmi.chassis.type: 10
dmi.chassis.vendor: Apple Inc.
dmi.chassis.version: Mac-742912EFDBEE19B3
dmi.modalias: dmi:bvnAppleInc.:bvrMBA41.88Z.0077.B12.1506081728:bd06/08/2015:svnAppleInc.:pnMacBookAir4,2:pvr1.0:rvnAppleInc.:rnMac-742912EFDBEE19B3:rvrMacBookAir4,2:cvnAppleInc.:ct10:cvrMac-742912EFDBEE19B3:
dmi.product.family: MacBook Air
dmi.product.name: MacBookAir4,2
dmi.product.version: 1.0
dmi.sys.vendor: Apple Inc.
hciconfig:

[Daniel van Vugt (vanvugt)]

Thanks for the bug report, but the driver is a kernel component so I am reassigning it.

Only if you saw the 'bluetoothd' process spinning would this be assigned to BlueZ.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This change was made by a bot.

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.14 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.14-rc5

[Norse (norse-dog)]

Reproes with the v4.14 kernel.

Power usage on idle is
4.14:~8W
4.13:~10W
4.10:~7W

There appears to have been a significant regression in power use from 4.10 to 4.13 that has been partially addressed in 4.14.

I got curious, and I get the same 100% busy report if I boot with the legacy 4.10.37 kernel now (whereas I did not before), so this might be an issue with powertop as upgraded with 17.10 and the bt driver might be a red herring. Is there a more reliable way to measure power usage?

[Norse (norse-dog)]

Reassigning to powertop package for a first look - I upgraded a PC laptop to 17.10, and I am seeing two usb devices (camera and keyboard) flagged as 100% busy and major consumers of power in powertop (whereas they were not before the upgrade).