linux-kernel - [PATCH] regulator: core: Propagate the regulator state in case of exclusive get

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Date: Tue, 12 Mar 2024 10:16:38 +0100
From: Kory Maincent <kory.maincent@...tlin.com>
To: linux-kernel@...r.kernel.org
Cc: Kory Maincent <kory.maincent@...tlin.com>,
	thomas.petazzoni@...tlin.com,
	Liam Girdwood <lgirdwood@...il.com>,
	Mark Brown <broonie@...nel.org>
Subject: [PATCH] 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@...tlin.com>
---
 drivers/regulator/core.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index a968dabb48f5..3f499761f8b0 100644
--- a/drivers/regulator/core.c
+++ b/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;
-- 
2.25.1