[PATCH togreg v3 2/2] iio: imu: inv_icm42607: restore runtime PM on system resume errors

[Linmao Li]

pm_runtime_force_suspend() leaves runtime PM disabled after it succeeds and
expects pm_runtime_force_resume() to restore runtime PM management during
system resume.

The resume callback returns early if enabling the vddio regulator or
synchronizing the register cache fails, skipping the matching
pm_runtime_force_resume() call. Runtime PM consequently remains disabled
after the system has resumed, so runtime autosuspend can no longer turn off
sensors enabled afterward.

Call pm_runtime_force_resume() on both error paths. Keep the first error as
the return value and report a runtime PM restore failure separately.

Fixes: 3007c1530f96 ("iio: imu: inv_icm42607: Add PM support for icm42607")
Signed-off-by: Linmao Li <lilinmao@xxxxxxxxxx>
---
Changes since v2:
- Restructure inv_icm42607_resume() along the lines Andy suggested:
  handle the error case in its own block and call
  pm_runtime_force_resume() directly on the success path.  No
  functional change.

Changes since v1:
- Split the device side of inv_icm42607_resume() into a helper so the
  PM bookkeeping stays in the wrapper.  No functional change.

 .../iio/imu/inv_icm42607/inv_icm42607_core.c  | 23 +++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/imu/inv_icm42607/inv_icm42607_core.c b/drivers/iio/imu/inv_icm42607/inv_icm42607_core.c
index 0da362967f63b..f4ef75da22c76 100644
--- a/drivers/iio/imu/inv_icm42607/inv_icm42607_core.c
+++ b/drivers/iio/imu/inv_icm42607/inv_icm42607_core.c
@@ -664,9 +664,8 @@ static int inv_icm42607_suspend(struct device *dev)
 	return 0;
 }
 
-static int inv_icm42607_resume(struct device *dev)
+static int inv_icm42607_resume_core(struct inv_icm42607_state *st)
 {
-	struct inv_icm42607_state *st = dev_get_drvdata(dev);
 	int ret;
 
 	ret = inv_icm42607_enable_vddio_reg(st);
@@ -675,9 +674,25 @@ static int inv_icm42607_resume(struct device *dev)
 
 	/* Sync the regcache again after regulator shutdown. */
 	regcache_mark_dirty(st->map);
-	ret = regcache_sync(st->map);
-	if (ret)
+
+	return regcache_sync(st->map);
+}
+
+static int inv_icm42607_resume(struct device *dev)
+{
+	struct inv_icm42607_state *st = dev_get_drvdata(dev);
+	int ret;
+
+	ret = inv_icm42607_resume_core(st);
+	if (ret) {
+		int rc;
+
+		rc = pm_runtime_force_resume(dev);
+		if (rc)
+			dev_warn(dev, "Failed to restore runtime PM state: %d\n", rc);
+
 		return ret;
+	}
 
 	return pm_runtime_force_resume(dev);
 }
-- 
2.25.1