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Vincent Guittot
74fb448630
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: 8234f6734c ("PM-runtime: Switch autosuspend over to using hrtimers")
Reported-by: Sunzhaosheng Sun(Zhaosheng) <[email protected]>
Signed-off-by: Vincent Guittot <[email protected]>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <[email protected]>