PM: runtime: fix denying of auto suspend in pm_suspend_timer_fn()
authorCharan Teja Kalla <quic_charante@quicinc.com>
Thu, 15 May 2025 06:41:25 +0000 (12:11 +0530)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Fri, 16 May 2025 20:05:43 +0000 (22:05 +0200)
commit40d3b40dce375d6f1c1dbf08d79eed3aed6c691d
tree85d2b08d95d5f0787d361628ddfda0f43d382136
parent495e7a6389c85003fc1ef4e893f0845e12fa9b95
PM: runtime: fix denying of auto suspend in pm_suspend_timer_fn()

pm_runtime_put_autosuspend() schedules a hrtimer to expire
at "dev->power.timer_expires". If the hrtimer's callback,
pm_suspend_timer_fn(), observes that the current time equals
"dev->power.timer_expires", it unexpectedly bails out instead of
proceeding with runtime suspend.

pm_suspend_timer_fn():

 if (expires > 0 && expires < ktime_get_mono_fast_ns()) {
  dev->power.timer_expires = 0;
  rpm_suspend(..)
 }

Additionally, as ->timer_expires is not cleared, all the future auto
suspend requests will not schedule hrtimer to perform auto suspend.

rpm_suspend():

 if ((rpmflags & RPM_AUTO) &&...) {
  if (!(dev->power.timer_expires && ...) { <-- this will fail.
  hrtimer_start_range_ns(&dev->power.suspend_timer,...);
  }
 }

Fix this by as well checking if current time reaches the set expiration.

Co-developed-by: Patrick Daly <quic_pdaly@quicinc.com>
Signed-off-by: Patrick Daly <quic_pdaly@quicinc.com>
Signed-off-by: Charan Teja Kalla <quic_charante@quicinc.com>
Link: https://patch.msgid.link/20250515064125.1211561-1-quic_charante@quicinc.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
drivers/base/power/runtime.c