Commit 16e3dbb1 changed the avr implementation of timer_read_time().
Unfortunately, it raised the possibility for timer_read_time() to be
out of sync with the scheduler's understanding of the current time.
In particular, it was common for the timer irq to overflow the 16bit
hardware counter once at startup, and this would lead to
timer_read_time() always returning a time ~4ms ahead of the scheduler
on 16Mhz chips. This resulted in "Move queue empty" errors.
To resolve this issue, only increment timer_high from timer_periodic()
and make sure the timer irqs start immediately after timer_init().
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
a1c61563a0