Bluetooth connection drops randomly

[acolombier]

Describe the bug

I am experiencing random Bluetooth connect drop between the Pi and an audio speaker. These drops appear after a random time, sometime few minutes, sometime few hours.

Once the the drop happen, the only fix is to reboot the PI: RFKILL report no block, Bluez report an Unknown Error, hciconfig hci0 down && hciconfig hci0 up has no effect, only the dmesg seems to spot a problem.

I am using LibreElec 9 (8.95.003)

I am using both onboard Wi-Fi and Bluetooth (I upgraded to 3 to 3B+ because I read the antenna design was changed and allow both in use)

To reproduce

Connect a Bluetooth speaker, and start playing audio on it.

Expected behaviour

No drop at any time, or at least no need for reboot

Actual behaviour

Bluetooth getting completely unusable after drop

System

• Which model of Raspberry Pi? Pi3B+
• Which OS and version (cat /etc/rpi-issue)? LibreElec 9 (8.95.003)
• Which firmware version (vcgencmd version)? bcefbb195b77d6b9a02dfbad0e1fff3b18122585 (Jan 9 2019 20:07:49)
• Which kernel version (uname -a)? 4.19.14

Logs

• dmesg*

[   xxxx] Bluetooth: hci0: hardware error 0x00
[   xxxx] Bluetooth: hci0: command 0x1003 tx timeout
[   xxxx] Bluetooth: hci0: command 0x1007 tx timeout
[   xxxx] Bluetooth: hci0: command 0x1009 tx timeout
<Keep repeating>

** Additional context **

I was using the RPI 3 before, with the exact same OS/Version, but this one didn't experience such a bug.

[pelwell]

We've recently received an updated Bluettooth firmware for the BCM43455 that hasn't made its way into a release yet. Can you see if it improves the symptoms for you?

1. Download the file from here.
2. Back-up the old file:

$ cp /lib/firmware/brcm/BCM4345C0.hcd BCM4345C0.hcd.orig

3. Copy in the new version:

$ sudo cp BCM4345C0_003.001.025.0156.0280.hcd /lib/firmware/brcm/BCM4345C0.hcd

4. Reboot.

To return to the original firmware, should you need to:

$ sudo cp BCM4345C0.hcd.orig /lib/firmware/brcm/BCM4345C0.hcd

[MilhouseVH]

@pelwell as this is LibreELEC the firmware should be copied to

/storage/.config/firmware/brcm/BCM4345C0.hcd

and there is no need to backup the existing firmware (which is in the read-only squashfs).

I've actually been including the new Bluetooth firmware in LibreELEC test builds for the last 10 days (not yet merged) since build #0117 so upgrading from 8.95.003 to a recent nightly will automatically include the new firmware (along with 4.19.17 in the latest #0126 release).

However upgrading only the Bluetooth firmware will result in a simplified before/after testing scenario, which might be the best option for now.

[pelwell]

Thanks, @MilhouseVH.

[acolombier]

Thanks @pelwell and @MilhouseVH. I have just installed the driver at the indicated location, I will come back here for the result of this fix.

[acolombier]

Unfortunately, I'm still experiencing the same issue. I don't have a computer with me currently, so I can't check if dmesg is logging the same error, but the symptoms are strictly the same. Do I have a way to ensure the new driver is loaded correctly?

[pelwell]

I haven't found a way of reading the version of the loaded firmware, but you can extract version info from the firmware file using strings:

pi@raspberrypi:~$ strings /lib/firmware/brcm/BCM4345C0.hcd | grep Raspberry
&BCM43455 37.4MHz Raspberry Pi 3+-0156

[orclex]

Same problem with bluetooth connection drops here. Only a pi restart helps, bluetooth restart does nothing.

Raspberry Pi 3B+
Raspbian GNU/Linux 10 (buster)
$ strings /lib/firmware/brcm/BCM4345C0.hcd | grep Raspberry
&BCM43455 37.4MHz Raspberry Pi 3+-0159

[iczero]

Same problem here. After what seems to be a random period of time, an error occurs and bluetooth stops working. Restarting hciuart reports the device is not responding.

$ strings /lib/firmware/brcm/BCM4345C0.hcd | grep Raspberry
&BCM43455 37.4MHz Raspberry Pi 3+-0156

[pelwell]

Which kernel versions are you all running (uname -a)? The recent 4.19.58 release includes a trial fix for a UART driver bug that would cause it to lose chunks of characters under the right conditions. You can try the new kernel by running sudo rpi-update (I'm not aware of any major issues with the current testing builds, but it's wise to make a backup first and not run bleeding-edge firmware on systems you can't afford to be without).

[JamesH65]

@acolombier @iczero @orclex Did moving to 4.19.58 fix your issues?

[notare-alname]

I had similar issues and rpi-update solved it for me.

[orclex]

@acolombier @iczero @orclex Did moving to 4.19.58 fix your issues?
Unfortunately I cannot test it anymore. I've disabled the bluetooth device and added an external bluetooth USB device which is working without problems. Now the RPi is working productive and I cannot experiment anymore. Maybe someone other can confirm that it is working now?

[rixwoodling]

This issue still appears to be open as OP has described on version 4.19.66, RPi3B+.
Bluetooth connects, audio plays. Then, audio drops at a random time and I am unable to determine why it drops and how to reconnect without rebooting as a workaround. It is worth noting that when attempting to 'power on' bluetooth after a dropout, it never does:

sudo bluetoothctl

Agent registered
[bluetooth]# show
: 
Powered: no
: 
[bluetooth]# power on
[bluetooth]# show
: 
Powered: no
: 
Failed to set power on: org.bluez.Error.Failed

---

Linux 4.19.66-v7+ #1253 SMP Thu Aug 15 11:49:46 BST 2019 armv71 GNU/Linux
&BCM43455 37.4MHz Raspberry Pi 3+-0156 # Raspbian 10 ( Buster )