USB port power sporadically shuts off
 

Running Slackware 14.0 on a Gigabyte Board, and periocially, perhaps once every 3 or 4 weeks, the power to the USB stops, and my phone stops charging. Sometimes it impacts all the USB ports, other times just a few.

I appears that I can turn it back on, but only for a short period, by placing "on" as in

echo on > /sys/bus/usb/devices/usb1/power/level # turn on

Any ideas on what I should be chasing?

Hi there,

is your computer running 24/7 all the time, or is it in standby mode?

If it's running full-on all the time, I've got no explanation for what you describe.

In standby, however, it is quite common, that USB power is retained (though not all boards and/or USB controllers do that), just like many network interfaces stay awake with the computer in standby. However, if there's a brief power outage (say, just a few seconds or even less than a second), the computer is completely powerless for an instant. When power returns, the computer enters standby mode again, but the peripherals like USB controllers or NICs have kind of "forgotten" their state.

No idea if that's really what you're experiencing, though.

[X] Doc CPU

It is up 24/7 and is not shut off. No standby.

I have since determined that this happens most when speed testing USB sticks, using commands such as:

dd if=/dev/sdc | wc