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>
diff --git a/drivers/mfd/twl6030-irq.c b/drivers/mfd/twl6030-irq.c
index a17b423..a014ec4 100644
--- a/drivers/mfd/twl6030-irq.c
+++ b/drivers/mfd/twl6030-irq.c
@@ -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 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 @@
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 @@
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_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");