[PATCH togreg 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>
---
Based on iio.git togreg at 0efaefce4e95.

 .../iio/imu/inv_icm42607/inv_icm42607_core.c  | 21 ++++++++++++-------
 1 file changed, 14 insertions(+), 7 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..5384596dd8d79 100644
--- a/drivers/iio/imu/inv_icm42607/inv_icm42607_core.c
+++ b/drivers/iio/imu/inv_icm42607/inv_icm42607_core.c
@@ -667,19 +667,26 @@ static int inv_icm42607_suspend(struct device *dev)
 static int inv_icm42607_resume(struct device *dev)
 {
 	struct inv_icm42607_state *st = dev_get_drvdata(dev);
+	int resume_ret;
 	int ret;
 
 	ret = inv_icm42607_enable_vddio_reg(st);
-	if (ret)
-		return ret;
+	if (!ret) {
+		/* Sync the regcache again after regulator shutdown. */
+		regcache_mark_dirty(st->map);
+		ret = regcache_sync(st->map);
+	}
+
+	resume_ret = pm_runtime_force_resume(dev);
+	if (ret) {
+		if (resume_ret)
+			dev_warn(dev, "Failed to restore runtime PM state: %d\n",
+				 resume_ret);
 
-	/* Sync the regcache again after regulator shutdown. */
-	regcache_mark_dirty(st->map);
-	ret = regcache_sync(st->map);
-	if (ret)
 		return ret;
+	}
 
-	return pm_runtime_force_resume(dev);
+	return resume_ret;
 }
 
 static int inv_icm42607_runtime_suspend(struct device *dev)
-- 
2.25.1