linux-kernel - [PATCH] regmap: silence GCC warning

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Date:	Sun, 30 Sep 2012 12:15:55 +0200
From:	Paul Bolle <pebolle@...cali.nl>
To:	Mark Brown <broonie@...nsource.wolfsonmicro.com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:	linux-kernel@...r.kernel.org
Subject: [PATCH] regmap: silence GCC warning

Building regmap.o triggers this GCC warning:
    drivers/base/regmap/regmap.c: In function ‘regmap_raw_read’:
    drivers/base/regmap/regmap.c:1172:6: warning: ‘ret’ may be used uninitialized in this function [-Wmaybe-uninitialized]

It seems 'ret' should always be set when this function returns. See, the
else-branch can leave 'ret' uninitialized only if 'val_count' is zero.
But if 'val_count' is zero regmap_volatile_range() will return true.
That implies that 'ret' will be set in the if-branch. ('val_count' could
be zero if 'val_len' is, for example, zero. That would be useless input,
however.)

Anyhow, initializing 'ret' to -EINVAL silences GCC and is harmless.

Signed-off-by: Paul Bolle <pebolle@...cali.nl>
---
I noticed this warning while building v3.6-rc7 on current Fedora 17,
using Fedora's default config.

 drivers/base/regmap/regmap.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index c241ae2..025f41c 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -1169,12 +1169,12 @@ int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 	size_t val_bytes = map->format.val_bytes;
 	size_t val_count = val_len / val_bytes;
 	unsigned int v;
-	int ret, i;
+	int i, ret = -EINVAL;
 
 	if (val_len % map->format.val_bytes)
-		return -EINVAL;
+		return ret;
 	if (reg % map->reg_stride)
-		return -EINVAL;
+		return ret;
 
 	map->lock(map);
 
-- 
1.7.11.4

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