Some link useful to poke around our USB devices:
Listing the USB devices:
cd /sys/bus/usb/devices/ ls -l
lspci | grep USB
Seeking for errors (it’s useful to remember 🙂 )
Talking with the device
Writing some parameter to the device (see docs to know what you’re doing):
echo 0 | sudo tee /sys/bus/usb/devices/usb2/power/autosuspend_delay_ms
or (as root)
# echo 0 > /sys/bus/usb/devices/usb2/power/autosuspend_delay_ms
ot talking to the module:
modprobe usbcore autosuspend=5
Resume a not working USB port
There’s a lot of people (mee too) that at some point has one/all USB port(s) not working.
I found that should be something related to the voltage protection of the port. It will be fixed turning off the PC (from the power supply) for 1 or 2 minutes.
If you cannot turn off the pc there’s another way: remove the usb modules then load them back:
# rmmod uhci_hcd # rmmod ehci_hcd # modprobe ehci_hcd # modprobe uhci_hcd
Remember that UHCI is for USB1 and EHCI is for USB2.