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ARM: OMAP2+: Fix suspcious RCU usage splats for omap_enter_idle_coupled 

[ 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 1098582a0f ("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 50d6b3cf94 ("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>
This commit is contained in:
Tony Lindgren 2021-01-10 21:09:11 +02:00 committed by Greg Kroah-Hartman
parent 2cb208ba0f
commit 2bb22cd4da
1 changed files with 8 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
arch/arm/mach-omap2/cpuidle44xx.c
View File

@ -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);