Score:0

Bluetooth Inactive (dead) Module btusb not found in directory /lib/modules/5.15.0-56

cy flag

I am using a Lenovo Thinkpad L470 and Ubuntu 20.04 LTS. Similar problems have been posed in the past, and I tried their solutions but to no avail.

Up to this morning bluetooth was running correctly on my laptop. Then I downloaded some drver thinking I was in another kernel than the one in the subject line. After that bluetooth quit on me.

I have tried removing and re-installing all the BT related packages, re-installed bluez, which tells me I have the most current version.

Lastly I did a modprobe btusb and got the return that btusb was not loaded. On top of that it could not be found in /lib/modules/5.15.0-56-generic.

So obviously something is missing.

Upon invoking systemctl status bluetooth I get the message

● bluetooth.service - Bluetooth service
     Loaded: loaded (/lib/systemd/system/bluetooth.service; enabled; vendor pre>
     Active: inactive (dead)
       Docs: man:bluetoothd(8)

Dez 04 21:16:30 thinkpad470 systemd[1]: Condition check resulted in Bluetooth s>
Dez 04 21:23:45 thinkpad470 systemd[1]: Condition check resulted in Bluetooth s>
lines 1-7/7 (END)

I hope someone can help out of the mess I created and help me get my bluetooth back.

Thanks! David

Score:1
ke flag

In terminal do sudo apt install --reinstall linux-modules-extra-5.15.0-56-generic

Then reboot

David avatar
cy flag
"modules-extra-5.15.0-56.generic" couldn't be found. Missing a repository? Can you help further? Thanks in advance! David
David avatar
cy flag
I did find a .deb version from ubuntu website. Since modules-extra is already installed the sw-installer would require that I first delete it before I can install the deb package. I fear that some other things might fail, like my ethernet and wifi apdaters and then I can no longer use the internet. What do you suggest? Again, thanks! David
Jeremy31 avatar
ke flag
Strange that you can have linux-modules-extra installed for the kernel and not have btusb.ko
David avatar
cy flag
I'm sure it was there before my mishap. BT was running fine until I began installing something that I should not have.
David avatar
cy flag
I found "Linux kernel extra modules for version 5.15.0 on 64 bit x86 SMP" in Synaptic Package Manager as installed (green). I thought I could re-install it to include the missing btusb. I saw this warning and am hesitant to proceed. What do you think? "You likely do not want to install this package directly. Instead, install the linux-generic meta-package, which will ensure that upgrades work correctly, and that supporting packages are also installed." Would I mess things up more?
Jeremy31 avatar
ke flag
Edit the question to include results for `dkms status`
David avatar
cy flag
I hope his helps:
David avatar
cy flag
david@thinkpad470:~$ dkms status rtbth, 3.9.7, 5.15.0-56-generic, x86_64: installed v4l2loopback, 0.12.3, 5.15.0-53-generic, x86_64: installed v4l2loopback, 0.12.3, 5.15.0-56-generic, x86_64: installed virtualbox, 6.1.38, 5.15.0-53-generic, x86_64: installed virtualbox, 6.1.38, 5.15.0-56-generic, x86_64: installed david@thinkpad470:~$
Jeremy31 avatar
ke flag
try `sudo dkms uninstall rtbth/3.9.7 && sudo dkms remove rtbth/3.9.7 --all` then reboot
David avatar
cy flag
thank you I will try it. Now that I know the name of the file to look for I did find btusb.ko in /usr/lib/modules/5.15.0-53-generic/kernel/drivers/bluetooth and the file rtk_btusb.ko in /usr/lib/modules/5.15.0-56-generic/kernel/drivers/bluetooth
David avatar
cy flag
Unfortunately it did not work. Looks like I really effed up my BT. This is name of the file (compressed) I began installing and broke off after I thought it was a bad idea: mpow_BH519A_driver+for+Linux.7z
Jeremy31 avatar
ke flag
It looks like installing that driver renames btusb, Try `cd /lib/modules/$(uname -r)/kernel/drivers/bluetooth && sudo mv btusb_bak btusb.ko` Then reboot
David avatar
cy flag
Did what you suggested. Didn't work. looked at BT packages in synaptic pkg mgr. All referenced kernel 5.15.0-53. Uh huh. Booted into this kernel and viola! BT works. Now how to troubleshoot differences between both kernels -53 and -56. Suggestions? Again, thank you for your time and patience helping me. I appreciate you for your knowledge and willingness to help us newbies. Unfortunately I know only enough about Linux to be dangerous to myself.
David avatar
cy flag
Did some more research. Found MANY users have problems with BT in kernel 5.15. for example: https://linuxreviews.org/Linux_Kernel_5.0.15_broke_Support_for_all_Older_Bluetooth_Devices_and_there%27s_no_fix_in_sight The "gurus" are saying downgrade to working kernel. 5.x kernel is EOL and not to expect any fixes for BT problem in it. We must all now wait patiently for new kernel and hope it works. Again, thanks!
Jeremy31 avatar
ke flag
I haven't had a bluetooth issue in 5.15 with my Intel or Broadcom Bluetooth devices
David avatar
cy flag
There might be an issue between some (older?) BT adapters and kernel 5.15.0-56. I have now found some other websites (quoted you one) in which this seems to be the case. Maybe my BT HW is one of the things that does not work with 5.15.0-56. How can I tell which BT adapter I have? For right now my laptop is running ok. As the saying goes, never touch a running system.
David avatar
cy flag
ADDENDUM: I found some USB-BT dongles that are fairly recent and tried them on my notebook. They didn't work either when using the kernel 5.15.0-56. I am not knowledgeable enough to figure out why this kernel has problems with my BT. Or vice versa. Again thank you!
Jeremy31 avatar
ke flag
Any result for `ls /lib/modules/5.15.0-56-generic/kernel/drivers/bluetooth | grep btusb` The btusb driver is needed for any USB Bluetooth device
Score:0
ro flag

In my case helped next (Ubuntu 22.04, Thinkpad E14):

Install the Bluetooth drivers:

$ sudo apt-get install bluez

Load the btusb module into the kernel:

$ sudo modprobe btusb

Check the status of the btusb module:

$ sudo modprobe -n -v btusb

p.s. rebooting, BIOS manipulation - not helped previously

Score:0
yt flag

I have the same issues since 5.15.0-56, on boot my bluetooth service is inactive (dead) with the same message in the log below.

What works for me is to run sudo modprobe btusb and then sudo systemctl restart bluetooth.service

I have yet to find a permanent fix for this, not sure why this issue isn't more widespread.

David avatar
cy flag
I have been being tutored by jeremy31. We have not found an answer for 5.15.0-56. I noticed in synaptic pkg mgr all BT packages referred to 5.15.0-53. I then booted linux with the 5.15.0-53 kernel and my BT service was active. Now we must find out what the difference between the two kernels is, as it relates to BT. Good luck!
Kuchiru avatar
yt flag
I found that it specifically has to do with the AX200 series chip, there are some bugs reported for this kernel (5.15) See: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1000403
David avatar
cy flag
How can I find out what chip my BT adapter (in laptop) has?
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