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Commit ab2b9260 authored by Todd Poynor's avatar Todd Poynor Committed by Samuel Ortiz
Browse files

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: default avatarTodd Poynor <toddpoynor@google.com>
Acked-by: default avatarSantosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: default avatarSamuel Ortiz <sameo@linux.intel.com>
parent d3efa4ed

drivers/mfd/twl6030-irq.c

+44 −2
Original line number Diff line number Diff line
@@ -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 @@ int twl6030_init_irq(int irq_num, unsigned irq_base, unsigned irq_end) 


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");