My GF has a Dell Vostro 3558 notebook that came with preinstalled Ubuntu 14.04 LTS system. Recently USB ports randomly fail. There's no pattern about it, no matter if the laptop is on charger or on battery, sometimes it works for a whole day, sometimes the ports fail after 30 minutes. When the failure happens, none of the USB ports work any more. If I issue lsusb it just hangs without any output. Also, the only way to restore USB functionality is to forcefully shut down the laptop with the power button, as if I try to correctly shut down the system, it just hangs.
Normally there's only a USB mouse used, but when the ports fail, no mouse, HDD or flash drive is recognized by the system. Power is still supplied to the ports as both the mouse's optical light and the flash drive's operating led blinks.
I checked syslog and found entries like this when the failure happens:
Jun 16 17:20:17 kriszta-Vostro-3558 kernel: [27807.306465] usb 2-5: reset high-speed USB device number 3 using xhci_hcd
Jun 16 17:20:17 kriszta-Vostro-3558 kernel: [27807.490473] usb 2-6: reset full-speed USB device number 4 using xhci_hcd
Jun 16 17:20:17 kriszta-Vostro-3558 kernel: [27807.618373] usb 2-8: reset high-speed USB device number 5 using xhci_hcd
Jun 16 17:20:17 kriszta-Vostro-3558 kernel: [27807.894272] usb 2-2: reset low-speed USB device number 6 using xhci_hcd
Jun 16 17:20:17 kriszta-Vostro-3558 kernel: [27807.911879] usb 2-2: ep 0x81 - rounding interval to 64 microframes, ep desc says 80 microframes
Jun 16 17:45:00 kriszta-Vostro-3558 kernel: [29290.676373] usb 2-2: reset low-speed USB device number 6 using xhci_hcd
Jun 16 17:45:00 kriszta-Vostro-3558 kernel: [29290.676840] usb 2-2: Device not responding to set address.
Jun 16 17:45:00 kriszta-Vostro-3558 kernel: [29290.880615] usb 2-2: Device not responding to set address.
Jun 16 17:45:00 kriszta-Vostro-3558 kernel: [29291.084024] usb 2-2: device not accepting address 6, error -71
I googled the error codes and tried a few solutions without luck. I.e.: I tried to remove and reload usb-hid but modprobe -r usbhid does nothing and if I try to kill it with signal 9 it refuses to die.
I suspect a hardware error, but I want to make sure. The built-in Dell diagnostics doesn't find any problems. The laptop is well under warranty. Do anyone have a solution for this, or should I just demand a motherboard replacement under warranty?