the problem usually occurs about once per day, seemingly at random, but occasionally two times, and occasionally zero times.devices connected are: a new STAR printer with it's own power supply, connected using a parallel to USB cable, and a low cost wired barcode scanner.ever since this problem began, i have added the follow kernel parameters to /etc/default/grub though the problem continues: GRUB_CMDLINE_LINUX_DEFAULT=quiet usbcore.autosuspend=-1 acpi=force apm=power_off irqpollthe computer in use is a thinkpad X200 running latest debian. hibernate and suspend are disabled on an OS level. i have tried changing the two USB related options in the BIOS but they don't seem to make a difference.when the error occurs, the computer will not shutdown properly, and hangs on a blinking cursor on a blank screen. the computer shuts down completely normally if it is shutdown before the error occurs.i have not tested a copy of the OS on other hardware, or the computer with a different OS.note that the failing USB ports are a bigger issue for me than the failing shutdown.the USB devices continue working as normal after a reboot, which suggests a software based problem to me, and hopefully an easy fix.update: the error last occurred at 11:53 and 150 lines of the /var/log/messages file can be found here: http://pastebin.com/P1KYGRqp
both USB ports randomly stop working
linux;usb;kernel modules;shutdown