regulator: core: Propagate the regulator state in case of exclusive get

Previously, performing an exclusive get on an already-enabled regulator
resulted in inconsistent state initialization between child and parent
regulators. While the child's counts were updated, its parent's counters
remained unaffected.

Consequently, attempting to disable an already-enabled exclusive regulator
triggered unbalanced disables warnings from its parent regulator.

This commit addresses the issue by propagating the enable state to the
parent regulator using a regulator_enable call. This ensures consistent
state management across the regulator hierarchy, preventing warnings!

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Link: https://msgid.link/r/20240312091638.1266167-1-kory.maincent@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: kmaincent

drivers/regulator/core.c

@@ -2274,6 +2274,17 @@ struct regulator *_regulator_get(struct device *dev, const char *id,
 		if (ret > 0) {
 			rdev->use_count = 1;
 			regulator->enable_count = 1;
+
+			/* Propagate the regulator state to its supply */
+			if (rdev->supply) {
+				ret = regulator_enable(rdev->supply);
+				if (ret < 0) {
+					destroy_regulator(regulator);
+					module_put(rdev->owner);
+					put_device(&rdev->dev);
+					return ERR_PTR(ret);
+				}
+			}
 		} else {
 			rdev->use_count = 0;
 			regulator->enable_count = 0;