Subject: Re: [PATCH] sound/soc/fsl/fsl_dma.c: add missing of_node_put

From: Timur Tabi <[email-masked]>
Date: Mon, 22 Aug 2011 09:03:17 -0500

Julia Lawall wrote:
> diff --git a/sound/soc/fsl/fsl_dma.c b/sound/soc/fsl/fsl_dma.c
> index 0efc04a..b33271b 100644
> --- a/sound/soc/fsl/fsl_dma.c
> +++ b/sound/soc/fsl/fsl_dma.c
> @@ -880,10 +880,12 @@ static struct device_node *find_ssi_node(struct device_node *dma_channel_np)
>  		np = of_parse_phandle(ssi_np, "fsl,playback-dma", 0);
>  		if (np == dma_channel_np)
>  			return ssi_np;
> +		of_node_put(np);
>  
>  		np = of_parse_phandle(ssi_np, "fsl,capture-dma", 0);
>  		if (np == dma_channel_np)
>  			return ssi_np;
> +		of_node_put(np);
>  	}

Thanks for catching the problem, Julia, but the fix is not quite correct.  My
code assumes that of_parse_phandle() doesn't claim the node, but it doesn't
actually use the node pointer, either.  All I care about is whether 'np' is
equal to dma_channel_np.  I'm not going to use 'np'.  So I think the real fix is
this:

@@ -880,10 +880,12 @@ static struct device_node *find_ssi_node(struct
device_node *dma_channel_np)
 		np = of_parse_phandle(ssi_np, "fsl,playback-dma", 0);
+		of_node_put(np);
 		if (np == dma_channel_np)
 			return ssi_np;

 		np = of_parse_phandle(ssi_np, "fsl,capture-dma", 0);
+		of_node_put(np);
 		if (np == dma_channel_np)
 			return ssi_np;
 	}

 	return NULL;

-- 
Timur Tabi
Linux kernel developer at Freescale