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ARM: clean up idle handlers 

Let's factor out the need_resched() check instead of having it duplicated
in every pm_idle implementations to avoid inconsistencies (omap2_pm_idle
is missing it already).

The forceful re-enablement of IRQs after pm_idle has returned can go.
The warning certainly doesn't trigger for existing users.

To get rid of the pm_idle calling convention oddity, let's introduce
arm_pm_idle() allowing for the local_irq_enable() to be factored out
from SOC specific implementations. The default pm_idle function becomes
a wrapper for arm_pm_idle and it takes care of enabling IRQs closer to
where they are initially disabled.

And finally move the comment explaining the reason for that turning off
of IRQs to a more proper location.

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-and-tested-by: Jamie Iles <jamie@jamieiles.com>
hifive-unleashed-5.1
Nicolas Pitre 2011-08-01 17:25:06 -04:00 committed by Nicolas Pitre
parent 3c0b2cef91
commit 4fa20439a8
2 changed files with 16 additions and 8 deletions
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1
arch/arm/include/asm/system.h
View File

@ -110,6 +110,7 @@ extern void cpu_init(void);
void soft_restart(unsigned long);
extern void (*arm_pm_restart)(char str, const char *cmd);
extern void (*arm_pm_idle)(void);
#define UDBG_UNDEFINED (1 << 0)
#define UDBG_SYSCALL (1 << 1)

23
arch/arm/kernel/process.c
View File

@ -181,12 +181,16 @@ void cpu_idle_wait(void)
EXPORT_SYMBOL_GPL(cpu_idle_wait);
/*
* This is our default idle handler. We need to disable
* interrupts here to ensure we don't miss a wakeup call.
* This is our default idle handler.
*/
void (*arm_pm_idle)(void);
static void default_idle(void)
{
if (!need_resched())
if (arm_pm_idle)
arm_pm_idle();
else
arch_idle();
local_irq_enable();
}
@ -215,6 +219,10 @@ void cpu_idle(void)
cpu_die();
#endif
/*
* We need to disable interrupts here
* to ensure we don't miss a wakeup call.
*/
local_irq_disable();
#ifdef CONFIG_PL310_ERRATA_769419
wmb();
@ -222,19 +230,18 @@ void cpu_idle(void)
if (hlt_counter) {
local_irq_enable();
cpu_relax();
} else {
} else if (!need_resched()) {
stop_critical_timings();
if (cpuidle_idle_call())
pm_idle();
start_critical_timings();
/*
* This will eventually be removed - pm_idle
* functions should always return with IRQs
* enabled.
* pm_idle functions must always
* return with IRQs enabled.
*/
WARN_ON(irqs_disabled());
} else
local_irq_enable();
}
}
leds_event(led_idle_end);
rcu_idle_exit();