[alsa-devel] [PATCH 1/2] sound/soc/davinci/davinci-mcasp.c: Return error code in failure

[Julia Lawall]

In this code, 0 is returned on failure, even though other
failures return -ENOMEM or other similar values.

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

// <smpl>
@a@
identifier alloc;
identifier ret;
constant C;
expression x;
@@

x = alloc(...);
if (x == NULL) { <+... \(ret = -C; \| return -C; \) ...+> }

@@
identifier f, a.alloc;
expression ret;
expression x,e1,e2,e3;
@@

ret = 0
... when != ret = e1
*x = alloc(...)
... when != ret = e2
if (x == NULL) { ... when != ret = e3
  return ret;
}
// </smpl>

Signed-off-by: Julia Lawall <julia at diku.dk>

---
Another call to platform_get_resource in the same function returns -ENODEV
on error, so I have used that value.

 sound/soc/davinci/davinci-mcasp.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/sound/soc/davinci/davinci-mcasp.c b/sound/soc/davinci/davinci-mcasp.c
index c8e97dc..86918ee 100644
--- a/sound/soc/davinci/davinci-mcasp.c
+++ b/sound/soc/davinci/davinci-mcasp.c
@@ -898,6 +898,7 @@ static int davinci_mcasp_probe(struct platform_device *pdev)
 	res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
 	if (!res) {
 		dev_err(&pdev->dev, "no DMA resource\n");
+		ret = -ENODEV;
 		goto err_release_region;
 	}
 
@@ -912,6 +913,7 @@ static int davinci_mcasp_probe(struct platform_device *pdev)
 	res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
 	if (!res) {
 		dev_err(&pdev->dev, "no DMA resource\n");
+		ret = -ENODEV;
 		goto err_release_region;
 	}