alarmtimer: Provide alarm_start_timer()

Alarm timers utilize hrtimers for normal operation and only switch to the
RTC on suspend. In order to catch already expired timers early and without
going through a timer interrupt cycle, provide a new start function which
internally uses hrtimer_start_range_ns_user().

If hrtimer_start_range_ns_user() detects an already expired timer, it does
not queue it. In that case remove the timer from the alarm base as well.

Return the status queued or not back to the caller to handle the early
expiry.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: John Stultz <jstultz@google.com>
Link: https://patch.msgid.link/20260408114952.332822525@kernel.org
This commit is contained in:
Thomas Gleixner 2026-04-08 13:54:11 +02:00
commit 183d00b727
2 changed files with 34 additions and 0 deletions