From: Tony Lindgren tony@atomide.com
[ Upstream commit 06862d789ddde8a99c1e579e934ca17c15a84755 ]
We get suspcious RCU usage splats with cpuidle in several places in omap_enter_idle_coupled() with the kernel debug options enabled:
RCU used illegally from extended quiescent state! ... (_raw_spin_lock_irqsave) (omap_enter_idle_coupled+0x17c/0x2d8) (omap_enter_idle_coupled) (cpuidle_enter_state) (cpuidle_enter_state_coupled) (cpuidle_enter)
Let's use RCU_NONIDLE to suppress these splats. Things got changed around with commit 1098582a0f6c ("sched,idle,rcu: Push rcu_idle deeper into the idle path") that started triggering these warnings.
For the tick_broadcast related calls, ideally we'd just switch over to using CPUIDLE_FLAG_TIMER_STOP for omap_enter_idle_coupled() to have the generic cpuidle code handle the tick_broadcast related calls for us and then just drop the tick_broadcast calls here.
But we're currently missing the call in the common cpuidle code for tick_broadcast_enable() that CPU1 hotplug needs as described in earlier commit 50d6b3cf9403 ("ARM: OMAP2+: fix lack of timer interrupts on CPU1 after hotplug").
Cc: Daniel Lezcano daniel.lezcano@linaro.org Cc: Paul E. McKenney paulmck@kernel.org Cc: Russell King rmk+kernel@armlinux.org.uk Acked-by: Paul E. McKenney paulmck@kernel.org Signed-off-by: Tony Lindgren tony@atomide.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm/mach-omap2/cpuidle44xx.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/arch/arm/mach-omap2/cpuidle44xx.c b/arch/arm/mach-omap2/cpuidle44xx.c index c8d317fafe2ea..de37027ad7587 100644 --- a/arch/arm/mach-omap2/cpuidle44xx.c +++ b/arch/arm/mach-omap2/cpuidle44xx.c @@ -151,10 +151,10 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev, (cx->mpu_logic_state == PWRDM_POWER_OFF);
/* Enter broadcast mode for periodic timers */ - tick_broadcast_enable(); + RCU_NONIDLE(tick_broadcast_enable());
/* Enter broadcast mode for one-shot timers */ - tick_broadcast_enter(); + RCU_NONIDLE(tick_broadcast_enter());
/* * Call idle CPU PM enter notifier chain so that @@ -166,7 +166,7 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev,
if (dev->cpu == 0) { pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state); - omap_set_pwrdm_state(mpu_pd, cx->mpu_state); + RCU_NONIDLE(omap_set_pwrdm_state(mpu_pd, cx->mpu_state));
/* * Call idle CPU cluster PM enter notifier chain @@ -178,7 +178,7 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev, index = 0; cx = state_ptr + index; pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state); - omap_set_pwrdm_state(mpu_pd, cx->mpu_state); + RCU_NONIDLE(omap_set_pwrdm_state(mpu_pd, cx->mpu_state)); mpuss_can_lose_context = 0; } } @@ -194,9 +194,9 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev, mpuss_can_lose_context) gic_dist_disable();
- clkdm_deny_idle(cpu_clkdm[1]); - omap_set_pwrdm_state(cpu_pd[1], PWRDM_POWER_ON); - clkdm_allow_idle(cpu_clkdm[1]); + RCU_NONIDLE(clkdm_deny_idle(cpu_clkdm[1])); + RCU_NONIDLE(omap_set_pwrdm_state(cpu_pd[1], PWRDM_POWER_ON)); + RCU_NONIDLE(clkdm_allow_idle(cpu_clkdm[1]));
if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD) && mpuss_can_lose_context) { @@ -222,7 +222,7 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev, cpu_pm_exit();
cpu_pm_out: - tick_broadcast_exit(); + RCU_NONIDLE(tick_broadcast_exit());
fail: cpuidle_coupled_parallel_barrier(dev, &abort_barrier);