diff options
| author | Vincent Guittot <vincent.guittot@linaro.org> | 2019-02-21 10:59:02 +0300 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2019-02-21 12:29:00 +0300 |
| commit | 74fb44863084275b952f21ec6a024af0e2e75cb8 (patch) | |
| tree | 6d5f00f222dba81808cdde588f2660ab8163810a /drivers | |
| parent | a3b22b9f11d9fbc48b0291ea92259a5a810e9438 (diff) | |
| download | linux-74fb44863084275b952f21ec6a024af0e2e75cb8.tar.xz | |
PM-runtime: Fix deadlock when canceling hrtimer
When rpm_resume() desactivates the autosuspend timer, it should only
try to cancel hrtimer but not wait for the handler to finish, because
both rpm_resume() and pm_suspend_timer_fn() take the power.lock.
A deadlock is possible as follows:
CPU0 CPU1
rpm_resume()
spin_lock_irqsave
pm_suspend_timer_fn()
spin_lock_irqsave
pm_runtime_deactivate_timer()
hrtimer_cancel()
It is sufficient to call hrtimer_try_to_cancel() from
pm_runtime_deactivate_timer(), because dev->power.timer_expires
reset to 0 by it, so use that function instead of hrtimer_cancel().
Fixes: 8234f6734c5d ("PM-runtime: Switch autosuspend over to using hrtimers")
Reported-by: Sunzhaosheng Sun(Zhaosheng) <sunzhaosheng@hisilicon.com>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/base/power/runtime.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 0ea2139c50d8..ccd296dbb95c 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -95,7 +95,7 @@ static void __update_runtime_status(struct device *dev, enum rpm_status status) static void pm_runtime_deactivate_timer(struct device *dev) { if (dev->power.timer_expires > 0) { - hrtimer_cancel(&dev->power.suspend_timer); + hrtimer_try_to_cancel(&dev->power.suspend_timer); dev->power.timer_expires = 0; } } |