mfd: Fix twl6030 lockdep recursion warning on setting wake IRQs

LOCKDEP explicitly sets all irq_desc locks as a single lock-class,
causing "possible recursive locking detected" when the TWL RTC
driver calls through enable_irq_wake to twl6030_irq_set_wake,
which recursively calls irq_set_irq_wake.  Although the
irq_desc and lock are different, LOCKDEP treats these as
equivalent, presumably due to problems that can be incurred
when locking more than one irq_desc, so best to avoid this.

Suspend/resume actions implemented as PM notifiers to avoid
touch the TWL core for this.

Signed-off-by: Todd Poynor <toddpoynor@google.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This commit is contained in:
Todd Poynor 2011-10-04 11:52:29 +02:00 committed by Samuel Ortiz
parent d3efa4edd5
commit ab2b9260df
1 changed files with 44 additions and 2 deletions

View File

@ -37,6 +37,7 @@
#include <linux/kthread.h>
#include <linux/i2c/twl.h>
#include <linux/platform_device.h>
#include <linux/suspend.h>
#include "twl-core.h"
@ -83,8 +84,42 @@ static int twl6030_interrupt_mapping[24] = {
/*----------------------------------------------------------------------*/
static unsigned twl6030_irq_base;
static int twl_irq;
static bool twl_irq_wake_enabled;
static struct completion irq_event;
static atomic_t twl6030_wakeirqs = ATOMIC_INIT(0);
static int twl6030_irq_pm_notifier(struct notifier_block *notifier,
unsigned long pm_event, void *unused)
{
int chained_wakeups;
switch (pm_event) {
case PM_SUSPEND_PREPARE:
chained_wakeups = atomic_read(&twl6030_wakeirqs);
if (chained_wakeups && !twl_irq_wake_enabled) {
if (enable_irq_wake(twl_irq))
pr_err("twl6030 IRQ wake enable failed\n");
else
twl_irq_wake_enabled = true;
} else if (!chained_wakeups && twl_irq_wake_enabled) {
disable_irq_wake(twl_irq);
twl_irq_wake_enabled = false;
}
break;
default:
break;
}
return NOTIFY_DONE;
}
static struct notifier_block twl6030_irq_pm_notifier_block = {
.notifier_call = twl6030_irq_pm_notifier,
};
/*
* This thread processes interrupts reported by the Primary Interrupt Handler.
@ -189,9 +224,12 @@ static inline void activate_irq(int irq)
int twl6030_irq_set_wake(struct irq_data *d, unsigned int on)
{
int twl_irq = (int)irq_get_chip_data(d->irq);
if (on)
atomic_inc(&twl6030_wakeirqs);
else
atomic_dec(&twl6030_wakeirqs);
return irq_set_irq_wake(twl_irq, on);
return 0;
}
/*----------------------------------------------------------------------*/
@ -354,6 +392,9 @@ int twl6030_init_irq(int irq_num, unsigned irq_base, unsigned irq_end)
status = PTR_ERR(task);
goto fail_kthread;
}
twl_irq = irq_num;
register_pm_notifier(&twl6030_irq_pm_notifier_block);
return status;
fail_kthread:
@ -367,6 +408,7 @@ fail_irq:
int twl6030_exit_irq(void)
{
unregister_pm_notifier(&twl6030_irq_pm_notifier_block);
if (twl6030_irq_base) {
pr_err("twl6030: can't yet clean up IRQs?\n");