[PATCH 4/5] drivers/media/platform/vino.c: fix error return code

[PATCH 4/5] drivers/media/platform/vino.c: fix error return code

[Peter Senna Tschudin]

From: Peter Senna Tschudin <peter.senna@gmail.com>

Convert a nonnegative error return code to a negative one, as returned
elsewhere in the function.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
(
if@p1 (\(ret < 0\|ret != 0\))
 { ... return ret; }
|
ret@p1 = 0
)
... when != ret = e1
    when != &ret
*if(...)
{
  ... when != ret = e2
      when forall
 return ret;
}

// </smpl>

Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>

---
 drivers/media/platform/vino.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/media/platform/vino.c b/drivers/media/platform/vino.c
index cc9110c..6654a28 100644
--- a/drivers/media/platform/vino.c
+++ b/drivers/media/platform/vino.c
@@ -2061,6 +2061,7 @@ static int vino_capture_next(struct vino_channel_settings *vcs, int start)
 	}
 	if (incoming == 0) {
 		dprintk("vino_capture_next(): no buffers available\n");
+		err = -ENOMEM;
 		goto out;
 	}
 

Re: [PATCH 4/5] drivers/media/platform/vino.c: fix error return code

[Ezequiel Garcia]

Hi Peter,

On Tue, Sep 4, 2012 at 1:14 PM, Peter Senna Tschudin
<peter.senna@gmail.com> wrote:
> From: Peter Senna Tschudin <peter.senna@gmail.com>
>
> Convert a nonnegative error return code to a negative one, as returned
> elsewhere in the function.
>
> A simplified version of the semantic match that finds this problem is as
> follows: (http://coccinelle.lip6.fr/)
>
> // <smpl>
> (
> if@p1 (\(ret < 0\|ret != 0\))
>  { ... return ret; }
> |
> ret@p1 = 0
> )
> ... when != ret = e1
>     when != &ret
> *if(...)
> {
>   ... when != ret = e2
>       when forall
>  return ret;
> }
>
> // </smpl>
>
> Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
>
> ---
>  drivers/media/platform/vino.c |    1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/media/platform/vino.c b/drivers/media/platform/vino.c
> index cc9110c..6654a28 100644
> --- a/drivers/media/platform/vino.c
> +++ b/drivers/media/platform/vino.c
> @@ -2061,6 +2061,7 @@ static int vino_capture_next(struct vino_channel_settings *vcs, int start)
>         }
>         if (incoming == 0) {
>                 dprintk("vino_capture_next(): no buffers available\n");
> +               err = -ENOMEM;
>                 goto out;
>         }
>

Mmm, this one doesn't look good.

I think the intention was to return zero, without error.
They driver tt's just double-checking for incoming data, if there's no incoming
data, then he simply exits.

Thanks,
Ezequiel.