ASoC: fsl_mqs: Fix error handling in probe

There are several problems in the error handling in fsl_mqs_probe().

1) "ret" isn't initialized on some paths.  GCC has a feature which
   warns about uninitialized variables but the code initializes "ret"
   to zero at the start of the function so the checking is turned off.
2) "gpr_np" is a pointer so initializing it to zero is confusing and
   generates a Sparse warning.
3) of_parse_phandle() doesn't return error pointers on error, it returns
   NULL.
4) If devm_snd_soc_register_component() fails then the function should
   free the "gpr_np".

Fixes: 9e28f6532c61 ("ASoC: fsl_mqs: Add MQS component driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20191004102208.GB823@mwanda
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/fsl/fsl_mqs.c b/sound/soc/fsl/fsl_mqs.c
index 7b9cab3a62e7cdc943375d20b1c1b22551fea251..f7fc44e8fb27701b64f67edf47f9ce8437c0c6b1 100644 (file)
--- a/sound/soc/fsl/fsl_mqs.c
+++ b/sound/soc/fsl/fsl_mqs.c
@@ -178,10 +178,10 @@ static const struct regmap_config fsl_mqs_regmap_config = {
 static int fsl_mqs_probe(struct platform_device *pdev)
 {
        struct device_node *np = pdev->dev.of_node;
-       struct device_node *gpr_np = 0;
+       struct device_node *gpr_np = NULL;
        struct fsl_mqs *mqs_priv;
        void __iomem *regs;
-       int ret = 0;
+       int ret;
 
        mqs_priv = devm_kzalloc(&pdev->dev, sizeof(*mqs_priv), GFP_KERNEL);
        if (!mqs_priv)
@@ -198,17 +198,16 @@ static int fsl_mqs_probe(struct platform_device *pdev)
 
        if (mqs_priv->use_gpr) {
                gpr_np = of_parse_phandle(np, "gpr", 0);
-               if (IS_ERR(gpr_np)) {
+               if (!gpr_np) {
                        dev_err(&pdev->dev, "failed to get gpr node by phandle\n");
-                       ret = PTR_ERR(gpr_np);
-                       goto out;
+                       return -EINVAL;
                }
 
                mqs_priv->regmap = syscon_node_to_regmap(gpr_np);
                if (IS_ERR(mqs_priv->regmap)) {
                        dev_err(&pdev->dev, "failed to get gpr regmap\n");
                        ret = PTR_ERR(mqs_priv->regmap);
-                       goto out;
+                       goto err_free_gpr_np;
                }
        } else {
                regs = devm_platform_ioremap_resource(pdev, 0);
@@ -229,7 +228,7 @@ static int fsl_mqs_probe(struct platform_device *pdev)
                if (IS_ERR(mqs_priv->ipg)) {
                        dev_err(&pdev->dev, "failed to get the clock: %ld\n",
                                PTR_ERR(mqs_priv->ipg));
-                       goto out;
+                       return PTR_ERR(mqs_priv->ipg);
                }
        }
 
@@ -237,17 +236,21 @@ static int fsl_mqs_probe(struct platform_device *pdev)
        if (IS_ERR(mqs_priv->mclk)) {
                dev_err(&pdev->dev, "failed to get the clock: %ld\n",
                        PTR_ERR(mqs_priv->mclk));
-               goto out;
+               ret = PTR_ERR(mqs_priv->mclk);
+               goto err_free_gpr_np;
        }
 
        dev_set_drvdata(&pdev->dev, mqs_priv);
        pm_runtime_enable(&pdev->dev);
 
-       return devm_snd_soc_register_component(&pdev->dev, &soc_codec_fsl_mqs,
+       ret = devm_snd_soc_register_component(&pdev->dev, &soc_codec_fsl_mqs,
                        &fsl_mqs_dai, 1);
-out:
-       if (!IS_ERR(gpr_np))
-               of_node_put(gpr_np);
+       if (ret)
+               goto err_free_gpr_np;
+       return 0;
+
+err_free_gpr_np:
+       of_node_put(gpr_np);
 
        return ret;
 }