Silencing hci0_malformed_msft annoyance

Introduction

I recently upgraded my machine and noticed I was being harassed by this particular message every boot: hci0_malformed_msft_vendor_event_0x02

This message is something to do with the Bluetooth drivers and so I looked into it and found that it is a warning for a non existent problem, and seemingly has no fix (unless you want to work on the kernel itself).

Theres a simple way of preventing this message from attacking your eyeballs every boot. It involves using boot parameters to reduce verbosity of logging.

Solution

I will go over implementing the fix for systemd-boot (which I use). You can apply this fix for any boot-loader (including grub), the boot parameter works the same.

Find your boot-entry configuration file:

My boot entry file is located at /boot/loader/entries/zen.conf (I use Zen Linux which is less bloated than the main-line kernel).

Now open it up with your editor of choice and navigate down to the options line. Append quiet loglevel=3 to it.

What this does is make the kernel only print messages of severity 3 (errors). You can read more about it here: kernel.org printk basics.

This is an advisable change in general because a lot of the warnings and messages printed by the kernel is regarding things you have no control over. So it is better to be out of sight and therefore out of mind.