[Bluetooth speaker BSP08WBT, playback] No bluetooth playback possible after resuming from suspend

[indigocat]

# What happens:
After resuming from suspend, audio playback to bluetooth speaker isn't possible, only the machine's internal speakers work.

Bluetooth speaker is a selectable option as output, but audio is not routed to bluetooth speaker, playback defaults to internal speakers even if bluetooth speaker is selected.

#What should happen:
When choosing the bluetooth speaker as audio output device, audio should be immediately routed to bluetooth speaker.

#Troubleshoting:
Already tried `pulseaudio --kill; pulseaudio --start`, `sudo hciconfig hci0 reset`, and `sudo service udev restart`. Problem persists.

I'm using kernel 4.4.0-134-generic.
Cannot use kernel 4.15+ on this machine (older Lenovo T410s), as performance drops impressively, due to sub-optimal disk i/o in comparison to 4.4, at least on this machine.

ProblemType: Bug
DistroRelease: elementary 0.4.1
Package: alsa-base 1.0.25+dfsg-0ubuntu5 [origin: Ubuntu]
ProcVersionSignature: Ubuntu 4.4.0-134.160-generic 4.4.140
Uname: Linux 4.4.0-134-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia wl
ApportVersion: 2.20.1-0ubuntu2.18
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: dmayr 13648 F.... pulseaudio
 /dev/snd/controlC0: dmayr 13648 F.... pulseaudio
CurrentDesktop: Pantheon
Date: Thu Aug 30 13:36:38 2018
InstallationDate: Installed on 2017-09-24 (340 days ago)
InstallationMedia: elementary OS 0.4.1 "Loki" - Stable amd64 (20170814)
PackageArchitecture: all
SourcePackage: alsa-driver
Symptom: audio
Symptom_Card: BSP08WBT
Symptom_Type: None of the above
Title: [BSP08WBT, playback] Playback problem
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 10/11/2012
dmi.bios.vendor: LENOVO
dmi.bios.version: 6UET70WW (1.50 )
dmi.board.name: 2924BV6
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvr6UET70WW(1.50):bd10/11/2012:svnLENOVO:pn2924BV6:pvrThinkPadT410s:rvnLENOVO:rn2924BV6:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 2924BV6
dmi.product.version: ThinkPad T410s
dmi.sys.vendor: LENOVO

[indigocat (indigocat)]

This has been happening randomly; yesterday, the speaker worked again.

For now, this report can be closed.