[mythtv-users] How To Prevent Disabling of USB Devices When Idle

[Nick Morrott]

On 29 September 2017 at 22:42, Jay Foster <jayf0ster at roadrunner.com> wrote:
> I have an Intel NUC 7I5BNH as a frontend.  I use an IO Gear wireless
> keyboard/mouse with it.  The interface to the frontend is a USB dongle.
> When the frontend is idle for enough time, the screen saver kicks in.
> Usually, pressing a key or moving the mouse (trackball) will wake up the
> frontend.  However, if more time passes by, the frontend kernel goes to
> sleep too, and no amount of key pressing or mouse moving will wake it up.  I
> suspect that the kernel is disabling the USB keyboard/mouse wireless dongle.
> Is there some way to prevent this?

Disabling power saving of individual USB devices is possible (and
necessary with some IR receivers too, IME).

You can follow a clear write-up here:

  http://hamwaves.com/usb.autosuspend/en/index.html

It boils down to poking power/control for the correct USB device
(under /sys/bus/usb/devices) and changing its status from 'auto'
(kernel can autosuspend the device) to 'on' (device is always on).

It may also be necessary to ensure that utilities like
laptop-mode-tools and powertop are not overwriting settings you are
manually applying.

Cheers,
Nick