[PATCH togreg v4 1/2] iio: imu: inv_icm42607: propagate runtime suspend errors

The runtime suspend callback returns success when updating PWR_MGMT0
fails.  The PM core then marks the device suspended even though the
shutdown outcome is unknown.  If the write did not reach the sensor, the
sensors remain running and draw power while the device is idle.

The condition need not persist.  If the bus error clears, a later sensor
access either reads the current PWR_MGMT0 value from hardware or retries
programming the requested enabled mode, allowing normal operation to
resume.

Return the underlying errno to the PM core.  -EAGAIN and -EBUSY retain
their transient-error semantics; other errors put runtime PM into an
error state and cause later PM acquires to fail until the status is
explicitly reset.  In the normal idle case, a successful system suspend
can perform that reset.  This leaves the transient-versus-fatal
classification to the PM core and matches the sibling ICM-42600 driver.

Keep a void wrapper for the managed teardown action, where errors can
only be logged.

Fixes: 3007c1530f96 ("iio: imu: inv_icm42607: Add PM support for icm42607")
Signed-off-by: Linmao Li <[email protected]>
---
Changes since v3:
- Expand the commit message with the practical effect and the recovery
  behaviour, as requested.  No code change.

This was found by code inspection.  No ICM-42607 hardware or
fault-injection setup was available.

 drivers/iio/imu/inv_icm42607/inv_icm42607_core.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/iio/imu/inv_icm42607/inv_icm42607_core.c b/drivers/iio/imu/inv_icm42607/inv_icm42607_core.c
index 190e998f7b8ef..0da362967f63b 100644
--- a/drivers/iio/imu/inv_icm42607/inv_icm42607_core.c
+++ b/drivers/iio/imu/inv_icm42607/inv_icm42607_core.c
@@ -537,9 +537,8 @@ static int inv_icm42607_enable_vddio_reg(struct inv_icm42607_state *st)
 	return 0;
 }
 
-static void inv_icm42607_sensors_off(void *_data)
+static int inv_icm42607_sensors_off(struct inv_icm42607_state *st)
 {
-	struct inv_icm42607_state *st = _data;
 	const struct device *dev = regmap_get_device(st->map);
 	int ret;
 
@@ -552,6 +551,13 @@ static void inv_icm42607_sensors_off(void *_data)
 					 st->conf.accel.mode);
 	if (ret)
 		dev_err(dev, "Unable to turn off sensors\n");
+
+	return ret;
+}
+
+static void inv_icm42607_sensors_off_action(void *data)
+{
+	inv_icm42607_sensors_off(data);
 }
 
 static void inv_icm42607_disable_vddio_reg(void *_data)
@@ -619,7 +625,7 @@ int inv_icm42607_core_probe(struct regmap *regmap,
 	 * Ensure if sensors get turned on at some point, they're turned off
 	 * as part of teardown.
 	 */
-	ret = devm_add_action_or_reset(dev, inv_icm42607_sensors_off, st);
+	ret = devm_add_action_or_reset(dev, inv_icm42607_sensors_off_action, st);
 	if (ret)
 		return ret;
 
@@ -688,8 +694,7 @@ static int inv_icm42607_runtime_suspend(struct device *dev)
 	 * however the tradeoff is that an unused sensor won't be
 	 * turned off until the entire chip is no longer in use.
 	 */
-	inv_icm42607_sensors_off(st);
-	return 0;
+	return inv_icm42607_sensors_off(st);
 }
 
 EXPORT_NS_GPL_DEV_PM_OPS(inv_icm42607_pm_ops, IIO_ICM42607) = {
-- 
2.25.1