tree e24f3365bd5ab2be800bb4d0afc11713e3ffd6cf
parent d7b35c9bd60270b00a1e8a675b20de8763ec03cd
author Andy Ross <andrew.j.ross@intel.com> 1537632112 -0700
committer Anas Nashif <anas.nashif@intel.com> 1539716590 -0400

idle: Fix tickless timeout behavior

If the idle code was detecting that it needed to sleep for less than
CONFIG_SYS_TICKLESS_IDLE_THRESH, then it would never call
z_clock_set_timeout() at all, which means that the system would never
wake up unless it already had a timeout scheduled!  Apparently we
lacked a test case to detect this condition.

Honestly this seems like a crazy feature to me.  There's no benefit in
delivering needless tick announcements.  If the system has the
capacity to enter deeper sleep for long timeouts, that's already
exposed via the PM APIs, the timer subsystem needn't be involved.
But... we actually have a test (tickless_concept) that looks at this,
so support it for now and consider deprecation later.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>