3 ms·

I'm running Gentoo Linux and haven't had issues with bluez. shrug

mikekchar 11y ago
My bluez problem may be related to using a Microsoft Sculpt keyboard. Was running Gentoo for many years on one of my boxes with the same bluetooth issues. Mainly bluez works fine if the device doesn't shut down for power saving. If it does, then bluez will often refuse to reconnect to it. I've tried to debug it but the code is not the most friendly ;-) It seems that the agent gets in a bad state where it thinks the device is both simultaneously connected and not connected. The easiest way to solve the problem is to restart the bluetooth service, reinitialize the agent and then hit a key on the keyboard. Doing anything else will cause it to get in the same bad state again. Occasionally you have to remove the device and re-pair. Every third update it will just start working and I'll think "Oh they fixed the bug". Then the next update breaks it again. I don't doubt that bluez must work well for some hardware, but for mine it is practically black magic to get it working. My only point in fingering bluez is to say that bluetooth going down is not a surprising event on my machine and isn't related to systemd at all. I suspect the same is true of the OP's box. It was probably just a coincidence that bluetooth died at the same time that systemd was installed.
- digi_owl 11y ago
  I am guessing the bluetooth radio was connected via USB. Thing about USB is that the Linux drivers were built around a misunderstanding regarding the sleep/suspend of USB devices. While the Linux code assumed the hardware was required to be up and ready in 2 minutes or less, the 2 minutes mentioned in the spec was just a suggested minimum wait time. Thus it would give up on devices that was still in the process of powering back on. That not to say that bluez have been in great shape in recent years. But then it is also a complicated concept for *nix, as it straddles root and user. You have their whole pairing interface on the user side, and then all the device nodes (HID, Audio, etc) on the root side.

My bluez problem may be related to using a Microsoft Sculpt keyboard. Was running Gentoo for many years on one of my boxes with the same bluetooth issues. Mainly bluez works fine if the device doesn't shut down for power saving. If it does, then bluez will often refuse to reconnect to it. I've tried to debug it but the code is not the most friendly ;-) It seems that the agent gets in a bad state where it thinks the device is both simultaneously connected and not connected. The easiest way to solve the problem is to restart the bluetooth service, reinitialize the agent and then hit a key on the keyboard. Doing anything else will cause it to get in the same bad state again. Occasionally you have to remove the device and re-pair. Every third update it will just start working and I'll think "Oh they fixed the bug". Then the next update breaks it again. I don't doubt that bluez must work well for some hardware, but for mine it is practically black magic to get it working. My only point in fingering bluez is to say that bluetooth going down is not a surprising event on my machine and isn't related to systemd at all. I suspect the same is true of the OP's box. It was probably just a coincidence that bluetooth died at the same time that systemd was installed.

digi_owl 11y ago
I am guessing the bluetooth radio was connected via USB. Thing about USB is that the Linux drivers were built around a misunderstanding regarding the sleep/suspend of USB devices. While the Linux code assumed the hardware was required to be up and ready in 2 minutes or less, the 2 minutes mentioned in the spec was just a suggested minimum wait time. Thus it would give up on devices that was still in the process of powering back on. That not to say that bluez have been in great shape in recent years. But then it is also a complicated concept for *nix, as it straddles root and user. You have their whole pairing interface on the user side, and then all the device nodes (HID, Audio, etc) on the root side.