Emulating scroll lock for kvm switch on the NSLU2

[Steinar Midtskogen <steinar@latinitas.org>]

I wish to share a USB device between two NSLU2's.  They're at a remote
site and the idea is that if the NSLU2 connected to the USB device
crashes/dies, the other will take over the device and continue
operations.  That would save me from a 300 km drive if the main NSLU2
crashes hard.

So I got a KVM switch which does what I wish.  It can be connected to
two computers and it's possible to grab control of the USB device by
hitting scroll lock twice.  So I wrote a program to hit scroll lock
twice for me, which I can run from command line:

#include <fcntl.h>
#include <stdio.h>
#include <linux/input.h>

int main(int argc, char** argv) {
  int i, fd;
  struct input_event event;

  fd = open("/dev/input/by-id/usb-Tangtop_USB2.0_DATA_SWITCH_9008151-event-kbd", O_RDWR);

  if (!fd)
    return 2;

  event.type = EV_KEY;
  event.code = KEY_SCROLLLOCK;
  for (i = 3; i >= 0; i--) {
    event.value = i & 1;
    write(fd, &event, sizeof(event));
    usleep(100000);
  }

  return 0;
}

This works on my x86 PC, but not on my NSLU2 running lenny.  The
switch is recognised and /dev/input is populated correctly, it seems.
Does anyone know why it still doesn't work?  Is what I'm trying at all
possible?

-- 
Steinar ; NIL DIFFICILE VOLENTI ; http://latinitas.org ; http://voksenlia.net