[alsa-devel] [PATCH 1/3] sound/soc/mxs/mxs-saif.c: keep pointer to resource so it can be freed

[Julia Lawall]

From: Julia Lawall <julia at diku.dk>

Add a new variable for storing resources accessed subsequent to the one
accessed using request_mem_region, so the one accessed using
request_mem_region can be released if needed.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r@
expression E, E1;
identifier f;
statement S1,S2,S3;
@@

if (E == NULL)
{
  ... when != if (E == NULL || ...) S1 else S2
      when != E = E1
*E->f
  ... when any
  return ...;
}
else S3
// </smpl>

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

---
Not even compile tested.

 sound/soc/mxs/mxs-saif.c |   19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/sound/soc/mxs/mxs-saif.c b/sound/soc/mxs/mxs-saif.c
index 401944c..76dc74d 100644
--- a/sound/soc/mxs/mxs-saif.c
+++ b/sound/soc/mxs/mxs-saif.c
@@ -617,7 +617,7 @@ static irqreturn_t mxs_saif_irq(int irq, void *dev_id)
 
 static int mxs_saif_probe(struct platform_device *pdev)
 {
-	struct resource *res;
+	struct resource *iores, *dmares;
 	struct mxs_saif *saif;
 	struct mxs_saif_platform_data *pdata;
 	int ret = 0;
@@ -655,35 +655,36 @@ static int mxs_saif_probe(struct platform_device *pdev)
 		goto failed_clk;
 	}
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res) {
+	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!iores) {
 		ret = -ENODEV;
 		dev_err(&pdev->dev, "failed to get io resource: %d\n",
 			ret);
 		goto failed_get_resource;
 	}
 
-	if (!request_mem_region(res->start, resource_size(res), "mxs-saif")) {
+	if (!request_mem_region(iores->start, resource_size(iores),
+				"mxs-saif")) {
 		dev_err(&pdev->dev, "request_mem_region failed\n");
 		ret = -EBUSY;
 		goto failed_get_resource;
 	}
 
-	saif->base = ioremap(res->start, resource_size(res));
+	saif->base = ioremap(iores->start, resource_size(iores));
 	if (!saif->base) {
 		dev_err(&pdev->dev, "ioremap failed\n");
 		ret = -ENODEV;
 		goto failed_ioremap;
 	}
 
-	res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
-	if (!res) {
+	dmares = platform_get_resource(pdev, IORESOURCE_DMA, 0);
+	if (!dmares) {
 		ret = -ENODEV;
 		dev_err(&pdev->dev, "failed to get dma resource: %d\n",
 			ret);
 		goto failed_ioremap;
 	}
-	saif->dma_param.chan_num = res->start;
+	saif->dma_param.chan_num = dmares->start;
 
 	saif->irq = platform_get_irq(pdev, 0);
 	if (saif->irq < 0) {
@@ -742,7 +743,7 @@ failed_get_irq2:
 failed_get_irq1:
 	iounmap(saif->base);
 failed_ioremap:
-	release_mem_region(res->start, resource_size(res));
+	release_mem_region(iores->start, resource_size(iores));
 failed_get_resource:
 	clk_put(saif->clk);
 failed_clk: