keyboard lost connection

[tom9672]

The keyboard lost connection happenes from time to time after using the 5.10 rt kernel, not sure about the issue caused by the keyborad itself or the kernel? One thing is it not happened before using rt kernel. Another thing is the keyboard not lost connection after I using a wireless keyboard instead of a usb keyboard. So I guess, may be the usb keyboard will sleep and lost connection? Is there any setting about the usb keyboard in the rt kernel? It should be perfect if the usb keyboard can works without suddenly disconnection. (Or, there is no settings about the usb keyboard in the rt kernel, the problem is just causing by the keyboard itself？)

[kdoren]

@tom9672 I'm not aware of any keyboard issues specific to PREEMPT_RT. A few random thoughts:

1. Which RPi and keyboard hardware are you using? Which kernel works? Which kernel has problem?
2. You could update the RPi firmware.
3. You could try 5.15 kernel to see if there is any difference vs 5.10.
4. I have posted release of both PREEMPT_RT and llat kernels of same version. Only difference is PREEMPT_RT. You could try both to see if same issue exists in llat version, or if it is indeed specific to PREEMPT_RT
5. USB Keyboards with LED lighting have been reported to have the potential for USB power issues. You could try running through a powered USB hub.

[tom9672]

Thanks for your reply, the 5th might be the issue I met. the keyboard disconnection issue not happened after using a keyboards without LED lighting.