[PATCH v4 1/3] iio: proximity: sx9310: keep the IRQ balanced across suspend and resume

[Arnav Kapoor <kapoorarnav43@gmail.com>]

sx9310_suspend() disables the interrupt first and returns with it still
disabled if a register access fails. Resume isn't called after a failed
suspend, so the interrupt is never enabled again. sx9310_resume() also
returns without enabling it on error.

Make the two mirror images: disable the interrupt as the last step of
suspend and enable it as the first step of resume, before anything can
fail. The driver works without an interrupt line, so skip both calls
when client->irq is 0, as sx_common already does.

Fixes: 72ad02b15d63 ("iio: Add SEMTECH SX9310/9311 sensor driver")
Signed-off-by: Arnav Kapoor <kapoorarnav43@gmail.com>
---
 drivers/iio/proximity/sx9310.c | 32 ++++++++++++++++++--------------
 1 file changed, 18 insertions(+), 14 deletions(-)

diff --git a/drivers/iio/proximity/sx9310.c b/drivers/iio/proximity/sx9310.c
index 79ba46d8a0aa..373037ca67d1 100644
--- a/drivers/iio/proximity/sx9310.c
+++ b/drivers/iio/proximity/sx9310.c
@@ -943,8 +943,6 @@ static int sx9310_suspend(struct device *dev)
 	u8 ctrl0;
 	int ret;
 
-	disable_irq_nosync(data->client->irq);
-
 	guard(mutex)(&data->mutex);
 	ret = regmap_read(data->regmap, SX9310_REG_PROX_CTRL0,
 			  &data->suspend_ctrl);
@@ -956,27 +954,33 @@ static int sx9310_suspend(struct device *dev)
 	if (ret)
 		return ret;
 
-	return regmap_write(data->regmap, SX9310_REG_PAUSE, 0);
+	ret = regmap_write(data->regmap, SX9310_REG_PAUSE, 0);
+	if (ret)
+		return ret;
+
+	/* Last, as resume isn't called if suspend fails. */
+	if (data->client->irq)
+		disable_irq_nosync(data->client->irq);
+
+	return 0;
 }
 
 static int sx9310_resume(struct device *dev)
 {
 	struct sx_common_data *data = iio_priv(dev_get_drvdata(dev));
+	struct regmap *map = data->regmap;
 	int ret;
 
-	scoped_guard(mutex, &data->mutex) {
-		ret = regmap_write(data->regmap, SX9310_REG_PAUSE, 1);
-		if (ret)
-			return ret;
+	if (data->client->irq)
+		enable_irq(data->client->irq);
 
-		ret = regmap_write(data->regmap, SX9310_REG_PROX_CTRL0,
-				   data->suspend_ctrl);
-		if (ret)
-			return ret;
-	}
+	guard(mutex)(&data->mutex);
 
-	enable_irq(data->client->irq);
-	return 0;
+	ret = regmap_write(map, SX9310_REG_PAUSE, 1);
+	if (ret)
+		return ret;
+
+	return regmap_write(map, SX9310_REG_PROX_CTRL0, data->suspend_ctrl);
 }
 
 static DEFINE_SIMPLE_DEV_PM_OPS(sx9310_pm_ops, sx9310_suspend, sx9310_resume);
-- 
2.53.0