linux-kernel - [PATCH v2] regmap: detach regmap from dev on regmap

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Message-ID: <20241127212233.330983-1-demonsingur@gmail.com>
Date: Wed, 27 Nov 2024 23:22:31 +0200
From: Cosmin Tanislav <demonsingur@...il.com>
To: 
Cc: Mark Brown <broonie@...nel.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	"Rafael J . Wysocki" <rafael@...nel.org>,
	linux-kernel@...r.kernel.org,
	Cosmin Tanislav <demonsingur@...il.com>
Subject: [PATCH v2] regmap: detach regmap from dev on regmap_exit

At the end of __regmap_init(), if dev is not NULL, regmap_attach_dev()
is called, which adds a devres reference to the regmap, to be able to
retrieve a dev's regmap by name using dev_get_regmap().

When calling regmap_exit, the opposite does not happen, and the
reference is kept until the dev is detached.

Add a regmap_detach_dev() function, export it and call it in
regmap_exit(), to make sure that the devres reference is not kept.

V2:
 * switch to static function

Fixes: 72b39f6f2b5a ("regmap: Implement dev_get_regmap()")
Signed-off-by: Cosmin Tanislav <demonsingur@...il.com>
---
 drivers/base/regmap/regmap.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 53131a7ede0a6..e3e2afc2c83c6 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -598,6 +598,17 @@ int regmap_attach_dev(struct device *dev, struct regmap *map,
 }
 EXPORT_SYMBOL_GPL(regmap_attach_dev);
 
+static int dev_get_regmap_match(struct device *dev, void *res, void *data);
+
+static int regmap_detach_dev(struct device *dev, struct regmap *map)
+{
+	if (!dev)
+		return 0;
+
+	return devres_release(dev, dev_get_regmap_release,
+			      dev_get_regmap_match, (void *)map->name);
+}
+
 static enum regmap_endian regmap_get_reg_endian(const struct regmap_bus *bus,
 					const struct regmap_config *config)
 {
@@ -1445,6 +1456,7 @@ void regmap_exit(struct regmap *map)
 {
 	struct regmap_async *async;
 
+	regmap_detach_dev(map->dev, map);
 	regcache_exit(map);
 
 	regmap_debugfs_exit(map);
-- 
2.47.0