[Dell DW375] bluetooth unavailable after rfkill hard (or soft) unblocking and after suspend/resume

[Thomas Mayer]

DELL Latitude E5510 has a hardware switch to disable and enable bluetooth and wifi devices ("hard blocking" in terms of rfkill). In terms of wifi, this works great: After hard unblocking, the device resumes back to normal operation without any manual intervention. That was also working with bluetooth as of ubuntu 14.04, kernel 4.2.

In ubuntu 16.04, kernel 4.4.0-31-generic, together with systemd, this is not working any more:

After hard blocking and unblocking

- bluetooth is not working at all
- the applet-indicator remains gray
- bluetooth cannot be enabled with the applet-indicator (see https://storage6.static.itmages.com/i/16/0717/h_1468721829_7715160_83cd33bfba.png). Applet-indicator remains gray
- rfkill list tells me that the kernel knows about the hard unblocking (turns from "yes" to "no"):
rfkill list bluetooth
2: dell-bluetooth: Bluetooth
 Soft blocked: no
 Hard blocked: no
8: hci0: Bluetooth
 Soft blocked: no
 Hard blocked: no

The device is a
sudo lsusb
Bus 002 Device 010: ID 413c:8187 Dell Computer Corp. DW375 Bluetooth Module

Workaround: After a

sudo service bluetooth restart

the bluetooth device turns back to normal operation and the applet-indicator turns from gray to black (available).

Suggested fix: Make the workaround obsolete.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: systemd 229-4ubuntu6
ProcVersionSignature: Ubuntu 4.4.0-31.50-generic 4.4.13
Uname: Linux 4.4.0-31-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
CurrentDesktop: GNOME-Flashback:Unity
Date: Sun Jul 17 04:00:58 2016
InstallationDate: Installed on 2014-11-29 (595 days ago)
InstallationMedia: Ubuntu 14.04.1 LTS "Trusty Tahr" - Release amd64 (20140722.2)
MachineType: Dell Inc. Latitude E5510
ProcKernelCmdLine: BOOT_IMAGE=/@/boot/vmlinuz-4.4.0-31-generic root=UUID=6408c2d9-1b60-43d7-9a7f-2dceeb40de28 ro rootflags=subvol=@ quiet splash vt.handoff=7
SourcePackage: systemd
UpgradeStatus: Upgraded to xenial on 2016-06-15 (31 days ago)
dmi.bios.date: 12/06/2013
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A16
dmi.board.name: 023HKR
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 9
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA16:bd12/06/2013:svnDellInc.:pnLatitudeE5510:pvr0001:rvnDellInc.:rn023HKR:rvrA00:cvnDellInc.:ct9:cvr:
dmi.product.name: Latitude E5510
dmi.product.version: 0001
dmi.sys.vendor: Dell Inc.

[Thomas Mayer (thomas303)]

This issue is not tlp related as still occurs without tlp (with laptop-mode-tools instead).

[Thomas Mayer (thomas303)]

Same behaviour for soft blocking the device:

rfkill block bluetooth

rfkill list bluetooth
2: dell-bluetooth: Bluetooth
 Soft blocked: yes
 Hard blocked: no

rfkill unblock bluetooth
rfkill list bluetooth
2: dell-bluetooth: Bluetooth
 Soft blocked: no
 Hard blocked: no
9: hci0: Bluetooth
 Soft blocked: no
 Hard blocked: no

Result: Bluetooth not working and indicator-applet is gray.

There's already a debian bug for soft unblocking: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=812150

[Thomas Mayer (thomas303)]

About every second time, I get a

rfkill unblock bluetooth
thomas@lat61:~$ rfkill list bluetooth
2: dell-bluetooth: Bluetooth
 Soft blocked: no
 Hard blocked: no
11: hci0: Bluetooth
 Soft blocked: yes
 Hard blocked: no

which is what debian bug 812150 is about.

Note that the soft block got released for "2: dell-bluetooth" but not for "11: hci0"

This is different from the hard unblock, where both hard blocks were released.

But no matter if hard or soft block and if released or not, bluetooth is not working after any sort of unblocking operation.

[Thomas Mayer (thomas303)]

For the unreleased soft blocking, I can work around with a second

rfkill unblock bluetooth

Executing this twice makes applet-indicator black again and bluetooth is operational (without "sudo service bluetooth restart" after a soft unblock).

To sum it up: There's three cases:

- hard unblock with released hard block
- soft unblock with unreleased soft block for hci0
- soft unblock with released soft block for hci0

All of them with gray indicator-applet and bluetooth non-operational.

[Thomas Mayer (thomas303)]

Plus, is bluetooth not operational after suspend/resume, while blocks are not set:

rfkill list bluetooth
2: dell-bluetooth: Bluetooth
 Soft blocked: no
 Hard blocked: no
13: hci0: Bluetooth
 Soft blocked: no
 Hard blocked: no

Again, a "sudo service bluetooth restart" helps after suspend/resume.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Eric Ding (ericding-alum)]

I'm experiencing a similar issue on Thinkpad x220 running Linux Mint 18 (based on Ubuntu 16.04) with kernel 4.4.0-21. In my case, rfkill unblock needs to be called twice in order to fully enable (and soft unblock) bluetooth:

# rfkill block bluetooth
# rfkill list bluetooth
0: tpacpi_bluetooth_sw: Bluetooth
 Soft blocked: yes
 Hard blocked: no
# rfkill unblock bluetooth
# rfkill list bluetooth
0: tpacpi_bluetooth_sw: Bluetooth
 Soft blocked: no
 Hard blocked: no
5: hci0: Bluetooth
 Soft blocked: yes
 Hard blocked: no

(At this stage, Bluetooth appears to be on in the Mint Bluetooth configuration dialog but can't see any devices).

# rfkill unblock bluetooth
# rfkill list bluetooth
0: tpacpi_bluetooth_sw: Bluetooth
 Soft blocked: no
 Hard blocked: no
5: hci0: Bluetooth
 Soft blocked: no
 Hard blocked: no

(Now Bluetooth works fully as expected).

[Thomas Mayer (thomas303)]

Looks as if one of these updates improved it for S2RAM, but not for hardware switch (I mean a real physical switch in my laptop for all wireless hardware)

libpulse0 1:8.0-0ubuntu3.3
libpulsedsp 1:8.0-0ubuntu3.3
libpulse-mainloop-glib0 1:8.0-0ubuntu3.3
pulseaudio 1:8.0-0ubuntu3.3
pulseaudio-module-bluetooth 1:8.0-0ubuntu3.3
pulseaudio-module-gconf 1:8.0-0ubuntu3.3
pulseaudio-module-x11 1:8.0-0ubuntu3.3
pulseaudio-module-zeroconf 1:8.0-0ubuntu3.3
pulseaudio-utils 1:8.0-0ubuntu3.3

linux-generic-hwe-16.04 4.8.0.58.29
linux-headers-4.8.0-58 4.8.0-58.63~16.04.1
linux-headers-4.8.0-58-generic 4.8.0-58.63~16.04.1
linux-headers-generic-hwe-16.04 4.8.0.58.29
linux-hwe-tools-4.8.0-58 4.8.0-58.63~16.04.1
linux-image-4.8.0-58-generic 4.8.0-58.63~16.04.1
linux-image-extra-4.8.0-58-generic 4.8.0-58.63~16.04.1
linux-image-generic-hwe-16.04 4.8.0.58.29
linux-tools-4.8.0-58-generic 4.8.0-58.63~16.04.1
linux-tools-generic-hwe-16.04 4.8.0.58.29

[Daniel van Vugt (vanvugt)]

Yes, we released pulseaudio 1:8.0-0ubuntu3.3 last week. But in testing that I too started to suspect that the v4.8 kernel (introduced in 16.04.2?) was helping to further reduce bluetooth bugs.