[PATCH] ov7670: clean up ov7670_read semantics

[PATCH] ov7670: clean up ov7670_read semantics

[Andres Salomon]

Cortland Setlow pointed out a bug in ov7670.c where the result from
ov7670_read() was just being checked for !0, rather than <0.  This
made me realize that ov7670_read's semantics were rather confusing;
it both fills in 'value' with the result, and returns it.  This is
goes against general kernel convention; so rather than fixing callers,
let's fix the function.

This makes ov7670_read return <0 in the case of an error, and 0 upon
success. Thus, code like:

res = ov7670_read(...);
if (!res)
	goto error;

..will work properly.

Signed-off-by: Cortland Setlow <csetlow@tower-research.com>
Signed-off-by: Andres Salomon <dilinger@debian.org>
---
 drivers/media/video/ov7670.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/drivers/media/video/ov7670.c b/drivers/media/video/ov7670.c
index 2bc6bdc..d7bfd30 100644
--- a/drivers/media/video/ov7670.c
+++ b/drivers/media/video/ov7670.c
@@ -406,8 +406,10 @@ static int ov7670_read(struct i2c_client *c, unsigned char reg,
 	int ret;
 
 	ret = i2c_smbus_read_byte_data(c, reg);
-	if (ret >= 0)
+	if (ret >= 0) {
 		*value = (unsigned char) ret;
+		ret = 0;
+	}
 	return ret;
 }
 
-- 
1.5.5.3

Re: [PATCH] ov7670: clean up ov7670_read semantics

[Jonathan Corbet]

[Added Mauro]

On Mon, 7 Jul 2008 01:41:26 +0000
Andres Salomon <dilinger@queued.net> wrote:

> This makes ov7670_read return <0 in the case of an error, and 0 upon
> success. 

The change seems fine to me.

Acked-by: Jonathan Corbet <corbet@lwn.net>

jon