- Disable interrupt when updating compare value in order to
make this operation atomical
- Increase minimum period for event timer. Systimer on BCM2835
is compare timer, so if minimum period is too small it might
be less then fraction of time between "read current value" and
"set compare timer" operations. It means that when timer is armed
actual counter value is more then compare value and it will take
whole cycle (~32sec for 1MHz timer) to fire interrupt.
Submitted by: Daisuke Aoyama <aoyama at peach.ne.jp>
bda4c885f5