[colug-432] blacklist usb device

[Rick Hornsby]

On 7/31/23 19:01, Jeff Frontz wrote:
> 
> I'm fairly certain this is all happening before udev even knows what's
> what -- I mean, you can turn off udev and see the same kernel messages
> (especially the "disconnect"), right?

Jeff's idea of disabling the USB controller was the right one. 
Fortunately for me - and this mobo - it didn't come down to de-soldering 
random chips.

One option that worked was to blacklist usbcore in the kernel arguments. 
I need other parts of the USB subsystem however, so that breaks things I 
need not broke.

The clue was buried in a SO post - /sys/bus/usb/drivers/hub/unbind

After iterating through the devices to see which one made a difference, 
adding

	'echo "1-1:1.0" > /sys/bus/usb/drivers/hub/unbind'

to /etc/rc.local fixes the problem. This stops the device from operating 
at the kernel level, below udev.

The keyboard/trackpad device cycles a couple of dozen times before 
rc.local runs, but that's fine. Load averages look way better now that 
udev isn't getting hammered.

21:46:53 up 9 min,  1 user,  load average: 0.00, 0.09, 0.10