linux-kernel - [PATCH v2] regulator: core: Prioritise consumer mappings over regulator name

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Date:   Tue, 13 Jun 2017 16:12:47 +0100
From:   Charles Keepax <ckeepax@...nsource.wolfsonmicro.com>
To:     <broonie@...nel.org>
CC:     <lgirdwood@...il.com>, <linux-kernel@...r.kernel.org>,
        <patches@...nsource.cirrus.com>
Subject: [PATCH v2] regulator: core: Prioritise consumer mappings over regulator name

Currently, when looking up a regulator supply, the regulator name
takes priority over the consumer mappings. As there are a lot of
regulator names that are in fairly common use (VDD, MICVDD, etc.) this
can easily lead to obtaining the wrong supply, when a system contains
two regulators that share a name.

The explicit consumer mappings contain much less ambiguity as they
specify both a name and a consumer device. As such prioritise those if
one exists and only fall back to the regulator name if there are no
matching explicit mappings.

Signed-off-by: Charles Keepax <ckeepax@...nsource.wolfsonmicro.com>
---

Changes since v1:
 - Move regulator_lookup_by_name till after the search of the map list

Thanks,
Charles

 drivers/regulator/core.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 919b7f1..91f87fa 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1462,7 +1462,7 @@ static struct regulator_dev *regulator_lookup_by_name(const char *name)
 static struct regulator_dev *regulator_dev_lookup(struct device *dev,
 						  const char *supply)
 {
-	struct regulator_dev *r;
+	struct regulator_dev *r = NULL;
 	struct device_node *node;
 	struct regulator_map *map;
 	const char *devname = NULL;
@@ -1489,10 +1489,6 @@ static struct regulator_dev *regulator_dev_lookup(struct device *dev,
 	if (dev)
 		devname = dev_name(dev);
 
-	r = regulator_lookup_by_name(supply);
-	if (r)
-		return r;
-
 	mutex_lock(&regulator_list_mutex);
 	list_for_each_entry(map, &regulator_map_list, list) {
 		/* If the mapping has a device set up it must match */
@@ -1511,6 +1507,10 @@ static struct regulator_dev *regulator_dev_lookup(struct device *dev,
 	if (r)
 		return r;
 
+	r = regulator_lookup_by_name(supply);
+	if (r)
+		return r;
+
 	return ERR_PTR(-ENODEV);
 }
 
-- 
2.1.4