ASoC: mt8173-rt5650: fix child-node lookup

This driver used the wrong OF-helper when looking up the optional
capture-codec child node during probe. Instead of searching just
children of the sound node, a tree-wide depth-first search starting at
the unrelated platform node was done. Not only could this end up
matching an unrelated node or no node at all; the platform node could
also be prematurely freed since of_find_node_by_name() drops a reference
to its first argument. This particular pattern has been observed leading
to crashes after probe deferrals in other drivers.

Fix this by dropping the broken call to of_find_node_by_name() and
keeping only the second, correct lookup using of_get_child_by_name()
while taking care not to bail out if the optional node is missing.

Note that this also addresses two capture-codec node-reference leaks
(one for each of the original helper calls).

Compile tested only.

Fixes: d349caeb0510 ("ASoC: mediatek: Add second I2S on mt8173-rt5650 machine driver")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/mediatek/mt8173/mt8173-rt5650.c b/sound/soc/mediatek/mt8173/mt8173-rt5650.c
index e69c141d8ed4c9a72d18187d1701c903cec41331..45fc2d2640aee604f6e24fe95fd1b3b48c483df2 100644 (file)
--- a/sound/soc/mediatek/mt8173/mt8173-rt5650.c
+++ b/sound/soc/mediatek/mt8173/mt8173-rt5650.c
@@ -274,15 +274,10 @@ static int mt8173_rt5650_dev_probe(struct platform_device *pdev)
        }
        mt8173_rt5650_codecs[1].of_node = mt8173_rt5650_codecs[0].of_node;
 
-       if (of_find_node_by_name(platform_node, "codec-capture")) {
-               np = of_get_child_by_name(pdev->dev.of_node, "codec-capture");
-               if (!np) {
-                       dev_err(&pdev->dev,
-                               "%s: Can't find codec-capture DT node\n",
-                               __func__);
-                       return -EINVAL;
-               }
+       np = of_get_child_by_name(pdev->dev.of_node, "codec-capture");
+       if (np) {
                ret = snd_soc_of_get_dai_name(np, &codec_capture_dai);
+               of_node_put(np);
                if (ret < 0) {
                        dev_err(&pdev->dev,
                                "%s codec_capture_dai name fail %d\n",