Hi, if they are USB devices, then chances are that you need to disable usb autosuspend
Code:
echo -1 >/sys/module/usbcore/parameters/autosuspend
to disable it for all usb devices
Code:
echo -1 >/sys/bus/usb/devices/.../power/autosuspend
(replacing ... by the path of your usb device) to disable it per device. to not have to run the first command at every reboot, just add
Code:
options usbcore autosuspend=0
to /etc/modprobe.conf (or usbcore.autosuspend=0 to you grub kernel command line)
Serafean