Comment 0 for bug 1371403

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Bryce Harrington (bryce) wrote : Disable USB autosuspend for Avocent SC Secure KVM

My mouse becomes temporarily become unresponsive to drags and clicks, until I right-click or give keyboard input, when it's been idle for a few seconds. The same thing affects the keyboard.

The mouse and keyboard are connected to a number of different computers via an 8-port Avocent SC Secure KVM. When the mouse and/or keyboard are directly attached to one of the PCs, there is no problem. I've tested with different keyboards and mice as well, and they're similarly messed up.

Only the computers running Ubuntu 14.04 are affected. Two of the computers are identical hardware, differing only in Ubuntu versions - the 14.04 one is affected but the one with 13.04 is not. I also have a machine with 12.04 on it connected to the KVM which is fine.

In powertop I notice that autosuspend is enabled for the Avocent. If I switch that off, then the problem disappears completely. I can also prevent it by issuing:

  echo 'on' > '/sys/bus/usb/devices/3-10/power/control';

where 3-10 is the Avocent (the number is different on each of my systems).

I notice in 42-usb-hid-pm.rules there is a rule for Avocent devices:

  # Catch-all for Avocent HID devices. Keyed off interface in order to only
  # trigger on HID class devices.
  ACTION=="add", SUBSYSTEM=="usb", ATTRS{idVendor}=="0624", ATTR{bInterfaceClass}=="03", TEST=="../power/control", ATTR{../power/control}="auto"

However my KVM device doesn't appear to have a bInterfaceClass defined.

In any case, the following udev rule corrects the problem for me:

ACTION=="add", SUBSYSTEM=="usb", ATTRS{idVendor}=="0624", ATTR{idProduct}=="0013", ATTR{product}=="SC Secure KVM", TEST=="power/control", ATTR{power/control}:="on"