A USB switch breaks USB sometimes.
by Luk from LinuxQuestions.org on (#6EB9N)
I have a cheap mechanical USB switch connected like this:
laptop1 ->
PC1 -> mechanical switch -> powered usb hub --> a keyboard & a wireless mouse dongle
laptop2 ->
The PC is running Arch, laptop1 is running AlmaLinux 9, laptop2 is running Windows 10.
I use it a lot to switch between devices. I probably switch close to 20-40 times per day. The problem only happens on Linux devices, never on Windows. It happens maybe once every 2 days or so. Basically, when it happens the Linux PC or laptop stops seeing the USB devices connected. It can't see the keyboard and mouse nor the powered USB hub. These devices don't show up in lsusb. There are no dmesg messages generated when the switch is switched.
What I have tried:
- disconnecting everything and powering down the hub, then reconnecting to the same USB port. - no difference
- simply connecting to a different USB port without powering down etc - it works fine
- restarting the Linux PC or laptop (without touching the devices) - it works fine
Is anyone else experiencing something like this? If this was happening on all my devices I'd just dismiss it as a dodgy USB switch, but in 3 weeks I have been using this switch it has happened many times on each Linux device and never on the windows device. So there is some difference how the hardware is used.
If anyone has any ideas how to troubleshoot it in absence of any messages from the kernel I'd love to hear them.
laptop1 ->
PC1 -> mechanical switch -> powered usb hub --> a keyboard & a wireless mouse dongle
laptop2 ->
The PC is running Arch, laptop1 is running AlmaLinux 9, laptop2 is running Windows 10.
I use it a lot to switch between devices. I probably switch close to 20-40 times per day. The problem only happens on Linux devices, never on Windows. It happens maybe once every 2 days or so. Basically, when it happens the Linux PC or laptop stops seeing the USB devices connected. It can't see the keyboard and mouse nor the powered USB hub. These devices don't show up in lsusb. There are no dmesg messages generated when the switch is switched.
What I have tried:
- disconnecting everything and powering down the hub, then reconnecting to the same USB port. - no difference
- simply connecting to a different USB port without powering down etc - it works fine
- restarting the Linux PC or laptop (without touching the devices) - it works fine
Is anyone else experiencing something like this? If this was happening on all my devices I'd just dismiss it as a dodgy USB switch, but in 3 weeks I have been using this switch it has happened many times on each Linux device and never on the windows device. So there is some difference how the hardware is used.
If anyone has any ideas how to troubleshoot it in absence of any messages from the kernel I'd love to hear them.