[PATCH AUTOSEL 5.9 24/33] cpuidle: tegra: Annotate tegra_pm_set_cpu_in_lp2() with RCU_NONIDLE

From: Sasha Levin
Date: Wed Nov 25 2020 - 10:42:42 EST


From: Dmitry Osipenko <digetx@xxxxxxxxx>

[ Upstream commit c39de538a06e76d89b7e598a71e16688009cd56c ]

Annotate tegra_pm_set[clear]_cpu_in_lp2() with RCU_NONIDLE in order to
fix lockdep warning about suspicious RCU usage of a spinlock during late
idling phase.

WARNING: suspicious RCU usage
...
include/trace/events/lock.h:13 suspicious rcu_dereference_check() usage!
...
(dump_stack) from (lock_acquire)
(lock_acquire) from (_raw_spin_lock)
(_raw_spin_lock) from (tegra_pm_set_cpu_in_lp2)
(tegra_pm_set_cpu_in_lp2) from (tegra_cpuidle_enter)
(tegra_cpuidle_enter) from (cpuidle_enter_state)
(cpuidle_enter_state) from (cpuidle_enter_state_coupled)
(cpuidle_enter_state_coupled) from (cpuidle_enter)
(cpuidle_enter) from (do_idle)
...

Tested-by: Peter Geis <pgwipeout@xxxxxxxxx>
Reported-by: Peter Geis <pgwipeout@xxxxxxxxx>
Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/cpuidle/cpuidle-tegra.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/cpuidle/cpuidle-tegra.c b/drivers/cpuidle/cpuidle-tegra.c
index e8956706a2917..191966dc8d023 100644
--- a/drivers/cpuidle/cpuidle-tegra.c
+++ b/drivers/cpuidle/cpuidle-tegra.c
@@ -189,7 +189,7 @@ static int tegra_cpuidle_state_enter(struct cpuidle_device *dev,
}

local_fiq_disable();
- tegra_pm_set_cpu_in_lp2();
+ RCU_NONIDLE(tegra_pm_set_cpu_in_lp2());
cpu_pm_enter();

switch (index) {
@@ -207,7 +207,7 @@ static int tegra_cpuidle_state_enter(struct cpuidle_device *dev,
}

cpu_pm_exit();
- tegra_pm_clear_cpu_in_lp2();
+ RCU_NONIDLE(tegra_pm_clear_cpu_in_lp2());
local_fiq_enable();

return err ?: index;
--
2.27.0