cpuidle: tegra: Annotate tegra_pm_set_cpu_in_lp2() with RCU_NONIDLE

PATCH Applied Dmitry Osipenko 2 participants 2 messages Nov 4, 2020 – Nov 12, 2020

Subsystems (2)

Tegra architecture support CPU idle time management framework

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Dmitry Osipenko

author

2020-11-04 13:21 UTC #0 lore raw

PATCH 1/1 cpuidle: tegra: Annotate tegra_pm_set_cpu_in_lp2() with RCU_NONIDLE

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 <[email protected]>

Reported-by Peter Geis <[email protected]>

Signed-off-by Dmitry Osipenko <[email protected]>

---
 drivers/cpuidle/cpuidle-tegra.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

drivers/cpuidle/cpuidle-tegra.c +2 -2

index e8956706a291..191966dc8d02 100644
@@ -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;

Signature · 1 line

2.27.0

Rafael J. Wysocki

maintainer Applied

2020-11-12 16:04 UTC #1 lore raw

Quoted 40 lines · Dmitry Osipenko

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 <[email protected]>
Reported-by Peter Geis <[email protected]>
Signed-off-by Dmitry Osipenko <[email protected]>
---
 drivers/cpuidle/cpuidle-tegra.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
drivers/cpuidle/cpuidle-tegra.c +1 -1
index e8956706a291..191966dc8d02 100644
@@ -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) {

drivers/cpuidle/cpuidle-tegra.c static int tegra_cpuidle_state_enter(struct cpuidle_device *dev,

Quoted 9 lines

drivers/cpuidle/cpuidle-tegra.c +1 -2

@@ -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;
--

Applied as a fix for 5.10-rc, thanks!