linux-kernel - [PATCH v2 1/2] regmap: cache: Return error in cache sync operations for REGCACHE

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Date:   Mon, 13 Mar 2023 08:18:11 +0100
From:   Alexander Stein <alexander.stein@...tq-group.com>
To:     Mark Brown <broonie@...nel.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Rafael J . Wysocki" <rafael@...nel.org>
Cc:     Alexander Stein <alexander.stein@...tq-group.com>,
        linux-kernel@...r.kernel.org
Subject: [PATCH v2 1/2] regmap: cache: Return error in cache sync operations for REGCACHE_NONE

There is no sense in doing a cache sync on REGCACHE_NONE regmaps.
Instead of panicking the kernel due to missing cache_ops, return an error
to client driver.

Signed-off-by: Alexander Stein <alexander.stein@...tq-group.com>
---
Changes in v2:
* Reworded the reasoning in the commit message
* Use WARN_ON to indicate there is an implementation error
* Return -EINVAL instead

 drivers/base/regmap/regcache.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index 362e043e26d86..8031007b4887d 100644
--- a/drivers/base/regmap/regcache.c
+++ b/drivers/base/regmap/regcache.c
@@ -349,6 +349,9 @@ int regcache_sync(struct regmap *map)
 	const char *name;
 	bool bypass;
 
+	if (WARN_ON(map->cache_type == REGCACHE_NONE))
+		return -EINVAL;
+
 	BUG_ON(!map->cache_ops);
 
 	map->lock(map->lock_arg);
@@ -418,6 +421,9 @@ int regcache_sync_region(struct regmap *map, unsigned int min,
 	const char *name;
 	bool bypass;
 
+	if (WARN_ON(map->cache_type == REGCACHE_NONE))
+		return -EINVAL;
+
 	BUG_ON(!map->cache_ops);
 
 	map->lock(map->lock_arg);
-- 
2.34.1