[PATCH 2/2] rtc: isl1208: Balance enable_irq_wake() with disable_irq_wake() on cleanup

[John Madieu]

isl1208_setup_irq() calls enable_irq_wake() after a successful
IRQ request, but the driver has no remove path that balances it.
The driver is devm-only, so on unbind devm releases the IRQ -
but enable_irq_wake() is not undone by IRQ release, so the wake
count for that IRQ stays incremented.

Each rebind therefore leaks one wake reference; the leak doubles
for the chip variant that has a separate evdet IRQ, since
isl1208_setup_irq() is then called twice during probe.

Register a devm action that calls disable_irq_wake() per IRQ.
While at it, check enable_irq_wake()'s return value:
on failure, propagate the error rather than silently registering
a disable action for an IRQ whose wake state was never enabled.

Fixes: 9ece7cd833a3 ("rtc: isl1208: Add "evdet" interrupt source for isl1219")
Signed-off-by: John Madieu <john.madieu.xa@xxxxxxxxxxxxxx>
---
 drivers/rtc/rtc-isl1208.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/rtc/rtc-isl1208.c b/drivers/rtc/rtc-isl1208.c
index c93998c53e7a..1de80fc9c9c9 100644
--- a/drivers/rtc/rtc-isl1208.c
+++ b/drivers/rtc/rtc-isl1208.c
@@ -822,6 +822,11 @@ static const struct nvmem_config isl1208_nvmem_config = {
 	.reg_write = isl1208_nvmem_write,
 };
 
+static void isl1208_disable_irq_wake_action(void *data)
+{
+	disable_irq_wake((unsigned long)data);
+}
+
 static int isl1208_setup_irq(struct i2c_client *client, int irq)
 {
 	int rc = devm_request_threaded_irq(&client->dev, irq, NULL,
@@ -831,7 +836,15 @@ static int isl1208_setup_irq(struct i2c_client *client, int irq)
 					client);
 	if (!rc) {
 		device_init_wakeup(&client->dev, true);
-		enable_irq_wake(irq);
+		rc = enable_irq_wake(irq);
+		if (rc)
+			return rc;
+
+		rc = devm_add_action_or_reset(&client->dev,
+					      isl1208_disable_irq_wake_action,
+					      (void *)(unsigned long)irq);
+		if (rc)
+			return rc;
 	} else {
 		dev_err(&client->dev,
 			"Unable to request irq %d, no alarm support\n",
-- 
2.25.1