linux-kernel - [PATCH] regulator: core: Don't link consumers on the same device

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Date:   Mon,  9 Jul 2018 13:54:02 +0100
From:   Mark Brown <broonie@...nel.org>
To:     Marek Szyprowski <m.szyprowski@...sung.com>,
        pascal paillet <p.paillet@...com>, benjamin.gaignard@...aro.org
Cc:     Krzysztof Kozlowski <krzk@...nel.org>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
        linux-kernel@...r.kernel.org, Mark Brown <broonie@...nel.org>
Subject: [PATCH] regulator: core: Don't link consumers on the same device

In some cases a device may end up supplying itself, for example when a
DCDC is used to improve the efficiency of LDOs or when a LDO is provided
to clean up sensitive supplies.  In these cases the driver core will
warn loudly about attempts to add links so suppress them here.

Reported-by: Marek Szyprowski <m.szyprowski@...sung.com>
Signed-off-by: Mark Brown <broonie@...nel.org>
---

Compile tested only.

 drivers/regulator/core.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index b5db0257bc40..1302e66e80ac 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1741,7 +1741,8 @@ struct regulator *_regulator_get(struct device *dev, const char *id,
 			rdev->use_count = 0;
 	}
 
-	device_link_add(dev, &rdev->dev, DL_FLAG_STATELESS);
+	if (dev != &rdev->dev)
+		device_link_add(dev, &rdev->dev, DL_FLAG_STATELESS);
 
 	return regulator;
 }
@@ -1840,7 +1841,7 @@ static void _regulator_put(struct regulator *regulator)
 			if (r->dev == regulator->dev)
 				count++;
 
-		if (count == 1)
+		if (count == 1 && regulator->dev != &rdev->dev)
 			device_link_remove(regulator->dev, &rdev->dev);
 
 		/* remove any sysfs entries */
-- 
2.18.0.rc2