[PATCH v2 0/6] Use helper function for_each_child_of_node_scoped()

[PATCH v2 0/6] Use helper function for_each_child_of_node_scoped()

[Ai Chao]

This patch series introduces wrapper functions for_each_child_of_node_scoped().

The for_each_child_of_node_scoped() helper provides a scope-based clean-up
functionality to put the device_node automatically, and as such, there is
no need to call of_node_put() directly.

Thus, use this helper to simplify the code.

Summary:

 - Patch 1 ASoC: ppc: Use helper function for_each_child_of_node_scoped()

 - Patch 2 ASoC: aoa: Use helper function for_each_child_of_node_scoped()

 - Patch 3 ASoC: renesas: Use helper function for_each_child_of_node_scoped()

 - Patch 4 ASoC: meson: Use helper function for_each_child_of_node_scoped()

 - Patch 5 ASoC: imx-card: Use helper function for_each_child_of_node_scoped()

 - Patch 6 ASoC: qcom: Use helper function for_each_child_of_node_scoped()

---
Changes in v2:
 - Fix error reported by kernel test rebot
 - Keep "node"
---
 sound/aoa/soundbus/i2sbus/core.c   |  5 +++--
 sound/ppc/tumbler.c                |  5 ++---
 sound/soc/fsl/imx-card.c           | 13 +++++------
 sound/soc/meson/axg-card.c         |  3 +--
 sound/soc/meson/meson-card-utils.c | 16 +++++---------
 sound/soc/qcom/lpass-cpu.c         |  3 +--
 sound/soc/qcom/qdsp6/q6afe-dai.c   |  3 +--
 sound/soc/qcom/qdsp6/q6asm-dai.c   |  4 +---
 sound/soc/renesas/rcar/core.c      | 35 ++++++++++--------------------
 sound/soc/renesas/rcar/ctu.c       |  8 ++-----
 sound/soc/renesas/rcar/dma.c       |  4 +---
 sound/soc/renesas/rcar/dvc.c       |  8 ++-----
 sound/soc/renesas/rcar/mix.c       |  8 ++-----
 sound/soc/renesas/rcar/src.c       | 10 ++-------
 sound/soc/renesas/rcar/ssi.c       | 18 +++++----------
 sound/soc/renesas/rcar/ssiu.c      |  7 ++----
 16 files changed, 46 insertions(+), 104 deletions(-)

-- 
2.47.1

[PATCH v2 1/6] ASoC: ppc: Use helper function for_each_child_of_node_scoped()

[Ai Chao]

The for_each_child_of_node_scoped() helper provides a scope-based
clean-up functionality to put the device_node automatically, and
as such, there is no need to call of_node_put() directly.

Thus, use this helper to simplify the code.

Signed-off-by: Ai Chao <aichao@kylinos.cn>
---
 sound/ppc/tumbler.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/sound/ppc/tumbler.c b/sound/ppc/tumbler.c
index 3c09660e1522..b81d0789b9fb 100644
--- a/sound/ppc/tumbler.c
+++ b/sound/ppc/tumbler.c
@@ -1343,7 +1343,7 @@ int snd_pmac_tumbler_init(struct snd_pmac *chip)
 	int i, err;
 	struct pmac_tumbler *mix;
 	const u32 *paddr;
-	struct device_node *tas_node, *np;
+	struct device_node *tas_node;
 	char *chipname;
 
 	request_module("i2c-powermac");
@@ -1358,13 +1358,12 @@ int snd_pmac_tumbler_init(struct snd_pmac *chip)
 	mix->anded_reset = 0;
 	mix->reset_on_sleep = 1;
 
-	for_each_child_of_node(chip->node, np) {
+	for_each_child_of_node_scoped(chip->node, np) {
 		if (of_node_name_eq(np, "sound")) {
 			if (of_property_read_bool(np, "has-anded-reset"))
 				mix->anded_reset = 1;
 			if (of_property_present(np, "layout-id"))
 				mix->reset_on_sleep = 0;
-			of_node_put(np);
 			break;
 		}
 	}
-- 
2.47.1

[PATCH v2 2/6] ASoC: aoa: Use helper function for_each_child_of_node_scoped()

[Ai Chao]

The for_each_child_of_node_scoped() helper provides a scope-based
clean-up functionality to put the device_node automatically, and
as such, there is no need to call of_node_put() directly.

Thus, use this helper to simplify the code.

Signed-off-by: Ai Chao <aichao@kylinos.cn>
---
 sound/aoa/soundbus/i2sbus/core.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/sound/aoa/soundbus/i2sbus/core.c b/sound/aoa/soundbus/i2sbus/core.c
index ce84288168e4..20a4c5891afc 100644
--- a/sound/aoa/soundbus/i2sbus/core.c
+++ b/sound/aoa/soundbus/i2sbus/core.c
@@ -207,6 +207,8 @@ static int i2sbus_add_dev(struct macio_dev *macio,
 			}
 		}
 	}
+	of_node_put(sound);
+
 	/* for the time being, until we can handle non-layout-id
 	 * things in some fabric, refuse to attach if there is no
 	 * layout-id property or we haven't been forced to attach.
@@ -335,7 +337,6 @@ static int i2sbus_add_dev(struct macio_dev *macio,
 
 static int i2sbus_probe(struct macio_dev* dev, const struct of_device_id *match)
 {
-	struct device_node *np;
 	int got = 0, err;
 	struct i2sbus_control *control = NULL;
 
@@ -347,7 +348,7 @@ static int i2sbus_probe(struct macio_dev* dev, const struct of_device_id *match)
 		return -ENODEV;
 	}
 
-	for_each_child_of_node(dev->ofdev.dev.of_node, np) {
+	for_each_child_of_node_scoped(dev->ofdev.dev.of_node, np) {
 		if (of_device_is_compatible(np, "i2sbus") ||
 		    of_device_is_compatible(np, "i2s-modem")) {
 			got += i2sbus_add_dev(dev, control, np);
-- 
2.47.1

[PATCH v2 3/6] ASoC: renesas: Use helper function for_each_child_of_node_scoped()

[Ai Chao]

The for_each_child_of_node_scoped() helper provides a scope-based
clean-up functionality to put the device_node automatically, and
as such, there is no need to call of_node_put() directly.

Thus, use this helper to simplify the code.

Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Ai Chao <aichao@kylinos.cn>
---
 sound/soc/renesas/rcar/core.c | 35 +++++++++++------------------------
 sound/soc/renesas/rcar/ctu.c  |  8 ++------
 sound/soc/renesas/rcar/dma.c  |  4 +---
 sound/soc/renesas/rcar/dvc.c  |  8 ++------
 sound/soc/renesas/rcar/mix.c  |  8 ++------
 sound/soc/renesas/rcar/src.c  | 10 ++--------
 sound/soc/renesas/rcar/ssi.c  | 18 +++++-------------
 sound/soc/renesas/rcar/ssiu.c |  7 ++-----
 8 files changed, 27 insertions(+), 71 deletions(-)

diff --git a/sound/soc/renesas/rcar/core.c b/sound/soc/renesas/rcar/core.c
index 30afc942d381..260c71888061 100644
--- a/sound/soc/renesas/rcar/core.c
+++ b/sound/soc/renesas/rcar/core.c
@@ -1075,7 +1075,6 @@ static void rsnd_parse_tdm_split_mode(struct rsnd_priv *priv,
 {
 	struct device *dev = rsnd_priv_to_dev(priv);
 	struct device_node *ssiu_np = rsnd_ssiu_of_node(priv);
-	struct device_node *np;
 	int is_play = rsnd_io_is_play(io);
 	int i;
 
@@ -1094,7 +1093,7 @@ static void rsnd_parse_tdm_split_mode(struct rsnd_priv *priv,
 		if (!node)
 			break;
 
-		for_each_child_of_node(ssiu_np, np) {
+		for_each_child_of_node_scoped(ssiu_np, np) {
 			if (np == node) {
 				rsnd_flags_set(io, RSND_STREAM_TDM_SPLIT);
 				dev_dbg(dev, "%s is part of TDM Split\n", io->name);
@@ -1154,21 +1153,18 @@ void rsnd_parse_connect_common(struct rsnd_dai *rdai, char *name,
 {
 	struct rsnd_priv *priv = rsnd_rdai_to_priv(rdai);
 	struct device *dev = rsnd_priv_to_dev(priv);
-	struct device_node *np;
 	int i;
 
 	if (!node)
 		return;
 
 	i = 0;
-	for_each_child_of_node(node, np) {
+	for_each_child_of_node_scoped(node, np) {
 		struct rsnd_mod *mod;
 
 		i = rsnd_node_fixed_index(dev, np, name, i);
-		if (i < 0) {
-			of_node_put(np);
+		if (i < 0)
 			break;
-		}
 
 		mod = mod_get(priv, i);
 
@@ -1217,16 +1213,13 @@ int rsnd_node_fixed_index(struct device *dev, struct device_node *node, char *na
 int rsnd_node_count(struct rsnd_priv *priv, struct device_node *node, char *name)
 {
 	struct device *dev = rsnd_priv_to_dev(priv);
-	struct device_node *np;
 	int i;
 
 	i = 0;
-	for_each_child_of_node(node, np) {
+	for_each_child_of_node_scoped(node, np) {
 		i = rsnd_node_fixed_index(dev, np, name, i);
-		if (i < 0) {
-			of_node_put(np);
+		if (i < 0)
 			return 0;
-		}
 		i++;
 	}
 
@@ -1250,7 +1243,7 @@ static int rsnd_dai_of_node(struct rsnd_priv *priv, int *is_graph)
 {
 	struct device *dev = rsnd_priv_to_dev(priv);
 	struct device_node *np = dev->of_node;
-	struct device_node *ports, *node;
+	struct device_node *node;
 	int nr = 0;
 	int i = 0;
 
@@ -1270,7 +1263,7 @@ static int rsnd_dai_of_node(struct rsnd_priv *priv, int *is_graph)
 
 	of_node_put(node);
 
-	for_each_child_of_node(np, node) {
+	for_each_child_of_node_scoped(np, node) {
 		if (!of_node_name_eq(node, RSND_NODE_DAI))
 			continue;
 
@@ -1279,7 +1272,6 @@ static int rsnd_dai_of_node(struct rsnd_priv *priv, int *is_graph)
 		i++;
 		if (i >= RSND_MAX_COMPONENT) {
 			dev_info(dev, "reach to max component\n");
-			of_node_put(node);
 			break;
 		}
 	}
@@ -1290,7 +1282,7 @@ static int rsnd_dai_of_node(struct rsnd_priv *priv, int *is_graph)
 	/*
 	 * Audio-Graph-Card
 	 */
-	for_each_child_of_node(np, ports) {
+	for_each_child_of_node_scoped(np, ports) {
 		node = rsnd_pick_endpoint_node_for_ports(ports, np);
 		if (!node)
 			continue;
@@ -1299,7 +1291,6 @@ static int rsnd_dai_of_node(struct rsnd_priv *priv, int *is_graph)
 		i++;
 		if (i >= RSND_MAX_COMPONENT) {
 			dev_info(dev, "reach to max component\n");
-			of_node_put(ports);
 			break;
 		}
 	}
@@ -1500,10 +1491,9 @@ static int rsnd_dai_probe(struct rsnd_priv *priv)
 	dai_i = 0;
 	if (is_graph) {
 		struct device_node *dai_np_port;
-		struct device_node *ports;
 		struct device_node *dai_np;
 
-		for_each_child_of_node(np, ports) {
+		for_each_child_of_node_scoped(np, ports) {
 			dai_np_port = rsnd_pick_endpoint_node_for_ports(ports, np);
 			if (!dai_np_port)
 				continue;
@@ -1520,14 +1510,11 @@ static int rsnd_dai_probe(struct rsnd_priv *priv)
 			}
 		}
 	} else {
-		struct device_node *node;
-		struct device_node *dai_np;
-
-		for_each_child_of_node(np, node) {
+		for_each_child_of_node_scoped(np, node) {
 			if (!of_node_name_eq(node, RSND_NODE_DAI))
 				continue;
 
-			for_each_child_of_node(node, dai_np) {
+			for_each_child_of_node_scoped(node, dai_np) {
 				__rsnd_dai_probe(priv, dai_np, np, dai_i, dai_i);
 				if (!rsnd_is_gen1(priv) && !rsnd_is_gen2(priv)) {
 					rdai = rsnd_rdai_get(priv, dai_i);
diff --git a/sound/soc/renesas/rcar/ctu.c b/sound/soc/renesas/rcar/ctu.c
index a26ec7b780cd..bd4c61f9fb3c 100644
--- a/sound/soc/renesas/rcar/ctu.c
+++ b/sound/soc/renesas/rcar/ctu.c
@@ -316,7 +316,6 @@ struct rsnd_mod *rsnd_ctu_mod_get(struct rsnd_priv *priv, int id)
 int rsnd_ctu_probe(struct rsnd_priv *priv)
 {
 	struct device_node *node;
-	struct device_node *np;
 	struct device *dev = rsnd_priv_to_dev(priv);
 	struct rsnd_ctu *ctu;
 	struct clk *clk;
@@ -344,7 +343,7 @@ int rsnd_ctu_probe(struct rsnd_priv *priv)
 
 	i = 0;
 	ret = 0;
-	for_each_child_of_node(node, np) {
+	for_each_child_of_node_scoped(node, np) {
 		ctu = rsnd_ctu_get(priv, i);
 
 		/*
@@ -357,16 +356,13 @@ int rsnd_ctu_probe(struct rsnd_priv *priv)
 		clk = devm_clk_get(dev, name);
 		if (IS_ERR(clk)) {
 			ret = PTR_ERR(clk);
-			of_node_put(np);
 			goto rsnd_ctu_probe_done;
 		}
 
 		ret = rsnd_mod_init(priv, rsnd_mod_get(ctu), &rsnd_ctu_ops,
 				    clk, RSND_MOD_CTU, i);
-		if (ret) {
-			of_node_put(np);
+		if (ret)
 			goto rsnd_ctu_probe_done;
-		}
 
 		i++;
 	}
diff --git a/sound/soc/renesas/rcar/dma.c b/sound/soc/renesas/rcar/dma.c
index 2342bbb6fe92..2035ce06fe4c 100644
--- a/sound/soc/renesas/rcar/dma.c
+++ b/sound/soc/renesas/rcar/dma.c
@@ -194,14 +194,12 @@ struct dma_chan *rsnd_dma_request_channel(struct device_node *of_node, char *nam
 	struct rsnd_priv *priv = rsnd_mod_to_priv(mod);
 	struct device *dev = rsnd_priv_to_dev(priv);
 	struct dma_chan *chan = NULL;
-	struct device_node *np;
 	int i = 0;
 
-	for_each_child_of_node(of_node, np) {
+	for_each_child_of_node_scoped(of_node, np) {
 		i = rsnd_node_fixed_index(dev, np, name, i);
 		if (i < 0) {
 			chan = NULL;
-			of_node_put(np);
 			break;
 		}
 
diff --git a/sound/soc/renesas/rcar/dvc.c b/sound/soc/renesas/rcar/dvc.c
index da91dd301aab..988cbddbc611 100644
--- a/sound/soc/renesas/rcar/dvc.c
+++ b/sound/soc/renesas/rcar/dvc.c
@@ -324,7 +324,6 @@ struct rsnd_mod *rsnd_dvc_mod_get(struct rsnd_priv *priv, int id)
 int rsnd_dvc_probe(struct rsnd_priv *priv)
 {
 	struct device_node *node;
-	struct device_node *np;
 	struct device *dev = rsnd_priv_to_dev(priv);
 	struct rsnd_dvc *dvc;
 	struct clk *clk;
@@ -352,7 +351,7 @@ int rsnd_dvc_probe(struct rsnd_priv *priv)
 
 	i = 0;
 	ret = 0;
-	for_each_child_of_node(node, np) {
+	for_each_child_of_node_scoped(node, np) {
 		dvc = rsnd_dvc_get(priv, i);
 
 		snprintf(name, RSND_DVC_NAME_SIZE, "%s.%d",
@@ -361,16 +360,13 @@ int rsnd_dvc_probe(struct rsnd_priv *priv)
 		clk = devm_clk_get(dev, name);
 		if (IS_ERR(clk)) {
 			ret = PTR_ERR(clk);
-			of_node_put(np);
 			goto rsnd_dvc_probe_done;
 		}
 
 		ret = rsnd_mod_init(priv, rsnd_mod_get(dvc), &rsnd_dvc_ops,
 				    clk, RSND_MOD_DVC, i);
-		if (ret) {
-			of_node_put(np);
+		if (ret)
 			goto rsnd_dvc_probe_done;
-		}
 
 		i++;
 	}
diff --git a/sound/soc/renesas/rcar/mix.c b/sound/soc/renesas/rcar/mix.c
index 024d91cc8748..aea74e703305 100644
--- a/sound/soc/renesas/rcar/mix.c
+++ b/sound/soc/renesas/rcar/mix.c
@@ -288,7 +288,6 @@ struct rsnd_mod *rsnd_mix_mod_get(struct rsnd_priv *priv, int id)
 int rsnd_mix_probe(struct rsnd_priv *priv)
 {
 	struct device_node *node;
-	struct device_node *np;
 	struct device *dev = rsnd_priv_to_dev(priv);
 	struct rsnd_mix *mix;
 	struct clk *clk;
@@ -316,7 +315,7 @@ int rsnd_mix_probe(struct rsnd_priv *priv)
 
 	i = 0;
 	ret = 0;
-	for_each_child_of_node(node, np) {
+	for_each_child_of_node_scoped(node, np) {
 		mix = rsnd_mix_get(priv, i);
 
 		snprintf(name, MIX_NAME_SIZE, "%s.%d",
@@ -325,16 +324,13 @@ int rsnd_mix_probe(struct rsnd_priv *priv)
 		clk = devm_clk_get(dev, name);
 		if (IS_ERR(clk)) {
 			ret = PTR_ERR(clk);
-			of_node_put(np);
 			goto rsnd_mix_probe_done;
 		}
 
 		ret = rsnd_mod_init(priv, rsnd_mod_get(mix), &rsnd_mix_ops,
 				    clk, RSND_MOD_MIX, i);
-		if (ret) {
-			of_node_put(np);
+		if (ret)
 			goto rsnd_mix_probe_done;
-		}
 
 		i++;
 	}
diff --git a/sound/soc/renesas/rcar/src.c b/sound/soc/renesas/rcar/src.c
index 7d73b183bda6..f47bf38c2f94 100644
--- a/sound/soc/renesas/rcar/src.c
+++ b/sound/soc/renesas/rcar/src.c
@@ -715,7 +715,6 @@ struct rsnd_mod *rsnd_src_mod_get(struct rsnd_priv *priv, int id)
 int rsnd_src_probe(struct rsnd_priv *priv)
 {
 	struct device_node *node;
-	struct device_node *np;
 	struct device *dev = rsnd_priv_to_dev(priv);
 	struct rsnd_src *src;
 	struct clk *clk;
@@ -742,14 +741,13 @@ int rsnd_src_probe(struct rsnd_priv *priv)
 	priv->src	= src;
 
 	i = 0;
-	for_each_child_of_node(node, np) {
+	for_each_child_of_node_scoped(node, np) {
 		if (!of_device_is_available(np))
 			goto skip;
 
 		i = rsnd_node_fixed_index(dev, np, SRC_NAME, i);
 		if (i < 0) {
 			ret = -EINVAL;
-			of_node_put(np);
 			goto rsnd_src_probe_done;
 		}
 
@@ -761,23 +759,19 @@ int rsnd_src_probe(struct rsnd_priv *priv)
 		src->irq = irq_of_parse_and_map(np, 0);
 		if (!src->irq) {
 			ret = -EINVAL;
-			of_node_put(np);
 			goto rsnd_src_probe_done;
 		}
 
 		clk = devm_clk_get(dev, name);
 		if (IS_ERR(clk)) {
 			ret = PTR_ERR(clk);
-			of_node_put(np);
 			goto rsnd_src_probe_done;
 		}
 
 		ret = rsnd_mod_init(priv, rsnd_mod_get(src),
 				    &rsnd_src_ops, clk, RSND_MOD_SRC, i);
-		if (ret) {
-			of_node_put(np);
+		if (ret)
 			goto rsnd_src_probe_done;
-		}
 
 skip:
 		i++;
diff --git a/sound/soc/renesas/rcar/ssi.c b/sound/soc/renesas/rcar/ssi.c
index 0c6424a1fcac..d52056caa3ec 100644
--- a/sound/soc/renesas/rcar/ssi.c
+++ b/sound/soc/renesas/rcar/ssi.c
@@ -1115,7 +1115,6 @@ void rsnd_parse_connect_ssi(struct rsnd_dai *rdai,
 	struct rsnd_priv *priv = rsnd_rdai_to_priv(rdai);
 	struct device *dev = rsnd_priv_to_dev(priv);
 	struct device_node *node;
-	struct device_node *np;
 	int i;
 
 	node = rsnd_ssi_of_node(priv);
@@ -1123,14 +1122,12 @@ void rsnd_parse_connect_ssi(struct rsnd_dai *rdai,
 		return;
 
 	i = 0;
-	for_each_child_of_node(node, np) {
+	for_each_child_of_node_scoped(node, np) {
 		struct rsnd_mod *mod;
 
 		i = rsnd_node_fixed_index(dev, np, SSI_NAME, i);
-		if (i < 0) {
-			of_node_put(np);
+		if (i < 0)
 			break;
-		}
 
 		mod = rsnd_ssi_mod_get(priv, i);
 
@@ -1163,7 +1160,6 @@ int __rsnd_ssi_is_pin_sharing(struct rsnd_mod *mod)
 int rsnd_ssi_probe(struct rsnd_priv *priv)
 {
 	struct device_node *node;
-	struct device_node *np;
 	struct device *dev = rsnd_priv_to_dev(priv);
 	struct rsnd_mod_ops *ops;
 	struct clk *clk;
@@ -1191,14 +1187,13 @@ int rsnd_ssi_probe(struct rsnd_priv *priv)
 	priv->ssi_nr	= nr;
 
 	i = 0;
-	for_each_child_of_node(node, np) {
+	for_each_child_of_node_scoped(node, np) {
 		if (!of_device_is_available(np))
 			goto skip;
 
 		i = rsnd_node_fixed_index(dev, np, SSI_NAME, i);
 		if (i < 0) {
 			ret = -EINVAL;
-			of_node_put(np);
 			goto rsnd_ssi_probe_done;
 		}
 
@@ -1210,7 +1205,6 @@ int rsnd_ssi_probe(struct rsnd_priv *priv)
 		clk = devm_clk_get(dev, name);
 		if (IS_ERR(clk)) {
 			ret = PTR_ERR(clk);
-			of_node_put(np);
 			goto rsnd_ssi_probe_done;
 		}
 
@@ -1223,7 +1217,6 @@ int rsnd_ssi_probe(struct rsnd_priv *priv)
 		ssi->irq = irq_of_parse_and_map(np, 0);
 		if (!ssi->irq) {
 			ret = -EINVAL;
-			of_node_put(np);
 			goto rsnd_ssi_probe_done;
 		}
 
@@ -1234,10 +1227,9 @@ int rsnd_ssi_probe(struct rsnd_priv *priv)
 
 		ret = rsnd_mod_init(priv, rsnd_mod_get(ssi), ops, clk,
 				    RSND_MOD_SSI, i);
-		if (ret) {
-			of_node_put(np);
+		if (ret)
 			goto rsnd_ssi_probe_done;
-		}
+
 skip:
 		i++;
 	}
diff --git a/sound/soc/renesas/rcar/ssiu.c b/sound/soc/renesas/rcar/ssiu.c
index 665e8b2db579..faf351126d57 100644
--- a/sound/soc/renesas/rcar/ssiu.c
+++ b/sound/soc/renesas/rcar/ssiu.c
@@ -478,17 +478,14 @@ void rsnd_parse_connect_ssiu(struct rsnd_dai *rdai,
 
 	/* use rcar_sound,ssiu if exist */
 	if (node) {
-		struct device_node *np;
 		int i = 0;
 
-		for_each_child_of_node(node, np) {
+		for_each_child_of_node_scoped(node, np) {
 			struct rsnd_mod *mod;
 
 			i = rsnd_node_fixed_index(dev, np, SSIU_NAME, i);
-			if (i < 0) {
-				of_node_put(np);
+			if (i < 0)
 				break;
-			}
 
 			mod = rsnd_ssiu_mod_get(priv, i);
 
-- 
2.47.1

[PATCH v2 4/6] ASoC: meson: Use helper function for_each_child_of_node_scoped()

[Ai Chao]

The for_each_child_of_node_scoped() helper provides a scope-based
clean-up functionality to put the device_node automatically, and
as such, there is no need to call of_node_put() directly.

Thus, use this helper to simplify the code.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202505210557.EpJig9BQ-lkp@intel.com/
Signed-off-by: Ai Chao <aichao@kylinos.cn>
---
 sound/soc/meson/axg-card.c         |  3 +--
 sound/soc/meson/meson-card-utils.c | 16 +++++-----------
 2 files changed, 6 insertions(+), 13 deletions(-)

diff --git a/sound/soc/meson/axg-card.c b/sound/soc/meson/axg-card.c
index a2dfccb7990f..b4dca80e15e4 100644
--- a/sound/soc/meson/axg-card.c
+++ b/sound/soc/meson/axg-card.c
@@ -222,7 +222,6 @@ static int axg_card_parse_codecs_masks(struct snd_soc_card *card,
 				       struct axg_dai_link_tdm_data *be)
 {
 	struct axg_dai_link_tdm_mask *codec_mask;
-	struct device_node *np;
 
 	codec_mask = devm_kcalloc(card->dev, link->num_codecs,
 				  sizeof(*codec_mask), GFP_KERNEL);
@@ -231,7 +230,7 @@ static int axg_card_parse_codecs_masks(struct snd_soc_card *card,
 
 	be->codec_masks = codec_mask;
 
-	for_each_child_of_node(node, np) {
+	for_each_child_of_node_scoped(node, np) {
 		snd_soc_of_get_slot_mask(np, "dai-tdm-slot-rx-mask",
 					 &codec_mask->rx);
 		snd_soc_of_get_slot_mask(np, "dai-tdm-slot-tx-mask",
diff --git a/sound/soc/meson/meson-card-utils.c b/sound/soc/meson/meson-card-utils.c
index cfc7f6e41ab5..0750dece9e69 100644
--- a/sound/soc/meson/meson-card-utils.c
+++ b/sound/soc/meson/meson-card-utils.c
@@ -137,7 +137,6 @@ int meson_card_set_be_link(struct snd_soc_card *card,
 			   struct device_node *node)
 {
 	struct snd_soc_dai_link_component *codec;
-	struct device_node *np;
 	int ret, num_codecs;
 
 	num_codecs = of_get_child_count(node);
@@ -154,19 +153,17 @@ int meson_card_set_be_link(struct snd_soc_card *card,
 	link->codecs = codec;
 	link->num_codecs = num_codecs;
 
-	for_each_child_of_node(node, np) {
+	for_each_child_of_node_scoped(node, np) {
 		ret = meson_card_parse_dai(card, np, codec);
-		if (ret) {
-			of_node_put(np);
+		if (ret)
 			return ret;
-		}
 
 		codec++;
 	}
 
 	ret = meson_card_set_link_name(card, link, node, "be");
 	if (ret)
-		dev_err(card->dev, "error setting %pOFn link name\n", np);
+		dev_err(card->dev, "error setting %pOFn link name\n", node);
 
 	return ret;
 }
@@ -198,7 +195,6 @@ static int meson_card_add_links(struct snd_soc_card *card)
 {
 	struct meson_card *priv = snd_soc_card_get_drvdata(card);
 	struct device_node *node = card->dev->of_node;
-	struct device_node *np;
 	int num, i, ret;
 
 	num = of_get_child_count(node);
@@ -212,12 +208,10 @@ static int meson_card_add_links(struct snd_soc_card *card)
 		return ret;
 
 	i = 0;
-	for_each_child_of_node(node, np) {
+	for_each_child_of_node_scoped(node, np) {
 		ret = priv->match_data->add_link(card, np, &i);
-		if (ret) {
-			of_node_put(np);
+		if (ret)
 			return ret;
-		}
 
 		i++;
 	}
-- 
2.47.1

[PATCH v2 5/6] ASoC: imx-card: Use helper function for_each_child_of_node_scoped()

[Ai Chao]

The for_each_child_of_node_scoped() helper provides a scope-based
clean-up functionality to put the device_node automatically, and
as such, there is no need to call of_node_put() directly.

Thus, use this helper to simplify the code.

Signed-off-by: Ai Chao <aichao@kylinos.cn>
---
 sound/soc/fsl/imx-card.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/sound/soc/fsl/imx-card.c b/sound/soc/fsl/imx-card.c
index 3686d468506b..bffdba4292b6 100644
--- a/sound/soc/fsl/imx-card.c
+++ b/sound/soc/fsl/imx-card.c
@@ -513,7 +513,6 @@ static int imx_card_parse_of(struct imx_card_data *data)
 	struct device_node *platform = NULL;
 	struct device_node *codec = NULL;
 	struct device_node *cpu = NULL;
-	struct device_node *np;
 	struct device *dev = card->dev;
 	struct snd_soc_dai_link *link;
 	struct dai_link_data *link_data;
@@ -552,11 +551,10 @@ static int imx_card_parse_of(struct imx_card_data *data)
 	link = card->dai_link;
 	link_data = data->link_data;
 
-	for_each_child_of_node(dev->of_node, np) {
+	for_each_child_of_node_scoped(dev->of_node, np) {
 		dlc = devm_kzalloc(dev, 2 * sizeof(*dlc), GFP_KERNEL);
 		if (!dlc) {
-			ret = -ENOMEM;
-			goto err_put_np;
+			return -ENOMEM;
 		}
 
 		link->cpus	= &dlc[0];
@@ -567,8 +565,8 @@ static int imx_card_parse_of(struct imx_card_data *data)
 
 		ret = of_property_read_string(np, "link-name", &link->name);
 		if (ret) {
-			dev_err(card->dev, "error getting codec dai_link name\n");
-			goto err_put_np;
+			return dev_err_probe(card->dev, ret,
+					     "error getting codec dai_link name\n");
 		}
 
 		cpu = of_get_child_by_name(np, "cpu");
@@ -722,8 +720,7 @@ static int imx_card_parse_of(struct imx_card_data *data)
 	of_node_put(cpu);
 	of_node_put(codec);
 	of_node_put(platform);
-err_put_np:
-	of_node_put(np);
+
 	return ret;
 }
 
-- 
2.47.1

[PATCH v2 6/6] ASoC: qcom: Use helper function for_each_child_of_node_scoped()

[Ai Chao]

The for_each_child_of_node_scoped() helper provides a scope-based
clean-up functionality to put the device_node automatically, and
as such, there is no need to call of_node_put() directly.

Thus, use this helper to simplify the code.

Signed-off-by: Ai Chao <aichao@kylinos.cn>
---
 sound/soc/qcom/lpass-cpu.c       | 3 +--
 sound/soc/qcom/qdsp6/q6afe-dai.c | 3 +--
 sound/soc/qcom/qdsp6/q6asm-dai.c | 4 +---
 3 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/sound/soc/qcom/lpass-cpu.c b/sound/soc/qcom/lpass-cpu.c
index 242bc16da36d..62f49fe46273 100644
--- a/sound/soc/qcom/lpass-cpu.c
+++ b/sound/soc/qcom/lpass-cpu.c
@@ -1046,7 +1046,6 @@ static unsigned int of_lpass_cpu_parse_sd_lines(struct device *dev,
 static void of_lpass_cpu_parse_dai_data(struct device *dev,
 					struct lpass_data *data)
 {
-	struct device_node *node;
 	int ret, i, id;
 
 	/* Allow all channels by default for backwards compatibility */
@@ -1056,7 +1055,7 @@ static void of_lpass_cpu_parse_dai_data(struct device *dev,
 		data->mi2s_capture_sd_mode[id] = LPAIF_I2SCTL_MODE_8CH;
 	}
 
-	for_each_child_of_node(dev->of_node, node) {
+	for_each_child_of_node_scoped(dev->of_node, node) {
 		ret = of_property_read_u32(node, "reg", &id);
 		if (ret || id < 0) {
 			dev_err(dev, "valid dai id not found: %d\n", ret);
diff --git a/sound/soc/qcom/qdsp6/q6afe-dai.c b/sound/soc/qcom/qdsp6/q6afe-dai.c
index 7d9628cda875..64735f2adf8f 100644
--- a/sound/soc/qcom/qdsp6/q6afe-dai.c
+++ b/sound/soc/qcom/qdsp6/q6afe-dai.c
@@ -962,10 +962,9 @@ static const struct snd_soc_component_driver q6afe_dai_component = {
 static void of_q6afe_parse_dai_data(struct device *dev,
 				    struct q6afe_dai_data *data)
 {
-	struct device_node *node;
 	int ret;
 
-	for_each_child_of_node(dev->of_node, node) {
+	for_each_child_of_node_scoped(dev->of_node, node) {
 		unsigned int lines[Q6AFE_MAX_MI2S_LINES];
 		struct q6afe_dai_priv_data *priv;
 		int id, i, num_lines;
diff --git a/sound/soc/qcom/qdsp6/q6asm-dai.c b/sound/soc/qcom/qdsp6/q6asm-dai.c
index a400c9a31fea..d7680dd3a3bb 100644
--- a/sound/soc/qcom/qdsp6/q6asm-dai.c
+++ b/sound/soc/qcom/qdsp6/q6asm-dai.c
@@ -1236,10 +1236,8 @@ static int of_q6asm_parse_dai_data(struct device *dev,
 {
 	struct snd_soc_dai_driver *dai_drv;
 	struct snd_soc_pcm_stream empty_stream;
-	struct device_node *node;
 	int ret, id, dir, idx = 0;
 
-
 	pdata->num_dais = of_get_child_count(dev->of_node);
 	if (!pdata->num_dais) {
 		dev_err(dev, "No dais found in DT\n");
@@ -1253,7 +1251,7 @@ static int of_q6asm_parse_dai_data(struct device *dev,
 
 	memset(&empty_stream, 0, sizeof(empty_stream));
 
-	for_each_child_of_node(dev->of_node, node) {
+	for_each_child_of_node_scoped(dev->of_node, node) {
 		ret = of_property_read_u32(node, "reg", &id);
 		if (ret || id >= MAX_SESSIONS || id < 0) {
 			dev_err(dev, "valid dai id not found:%d\n", ret);
-- 
2.47.1

Re: [PATCH v2 1/6] ASoC: ppc: Use helper function for_each_child_of_node_scoped()

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 500 bytes --]

On Thu, May 22, 2025 at 01:02:54PM +0800, Ai Chao wrote:
> The for_each_child_of_node_scoped() helper provides a scope-based
> clean-up functionality to put the device_node automatically, and
> as such, there is no need to call of_node_put() directly.
> 
> Thus, use this helper to simplify the code.
> 
> Signed-off-by: Ai Chao <aichao@kylinos.cn>
> ---
>  sound/ppc/tumbler.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)

This is for ALSA, not ASoC (same for patch 2).

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

Re: [PATCH v2 2/6] ASoC: aoa: Use helper function for_each_child_of_node_scoped()

[Johannes Berg]

On Thu, 2025-05-22 at 13:02 +0800, Ai Chao wrote:
> The for_each_child_of_node_scoped() helper provides a scope-based
> clean-up functionality to put the device_node automatically, and
> as such, there is no need to call of_node_put() directly.
> 
> Thus, use this helper to simplify the code.

> -	for_each_child_of_node(dev->ofdev.dev.of_node, np) {
> +	for_each_child_of_node_scoped(dev->ofdev.dev.of_node, np) {
>  		if (of_device_is_compatible(np, "i2sbus") ||
>  		    of_device_is_compatible(np, "i2s-modem")) {
>  			got += i2sbus_add_dev(dev, control, np);

Given the structure of this code, this either fixes a leak, or is wrong.
I really don't know which of those two it is, it's been decades, but
either way it's not a change that simply "simplif[ies] the code".

johannes

Re: [PATCH v2 6/6] ASoC: qcom: Use helper function for_each_child_of_node_scoped()

[Dmitry Baryshkov]

On Thu, May 22, 2025 at 01:02:59PM +0800, Ai Chao wrote:
> The for_each_child_of_node_scoped() helper provides a scope-based
> clean-up functionality to put the device_node automatically, and
> as such, there is no need to call of_node_put() directly.

There are no calls to of_node_put() in the commit. So the commit message
is incorrect / not-applicable.

> 
> Thus, use this helper to simplify the code.
> 
> Signed-off-by: Ai Chao <aichao@kylinos.cn>
> ---
>  sound/soc/qcom/lpass-cpu.c       | 3 +--
>  sound/soc/qcom/qdsp6/q6afe-dai.c | 3 +--
>  sound/soc/qcom/qdsp6/q6asm-dai.c | 4 +---
>  3 files changed, 3 insertions(+), 7 deletions(-)
> 
> diff --git a/sound/soc/qcom/lpass-cpu.c b/sound/soc/qcom/lpass-cpu.c
> index 242bc16da36d..62f49fe46273 100644
> --- a/sound/soc/qcom/lpass-cpu.c
> +++ b/sound/soc/qcom/lpass-cpu.c
> @@ -1046,7 +1046,6 @@ static unsigned int of_lpass_cpu_parse_sd_lines(struct device *dev,
>  static void of_lpass_cpu_parse_dai_data(struct device *dev,
>  					struct lpass_data *data)
>  {
> -	struct device_node *node;
>  	int ret, i, id;
>  
>  	/* Allow all channels by default for backwards compatibility */
> @@ -1056,7 +1055,7 @@ static void of_lpass_cpu_parse_dai_data(struct device *dev,
>  		data->mi2s_capture_sd_mode[id] = LPAIF_I2SCTL_MODE_8CH;
>  	}
>  
> -	for_each_child_of_node(dev->of_node, node) {
> +	for_each_child_of_node_scoped(dev->of_node, node) {
>  		ret = of_property_read_u32(node, "reg", &id);
>  		if (ret || id < 0) {
>  			dev_err(dev, "valid dai id not found: %d\n", ret);
> diff --git a/sound/soc/qcom/qdsp6/q6afe-dai.c b/sound/soc/qcom/qdsp6/q6afe-dai.c
> index 7d9628cda875..64735f2adf8f 100644
> --- a/sound/soc/qcom/qdsp6/q6afe-dai.c
> +++ b/sound/soc/qcom/qdsp6/q6afe-dai.c
> @@ -962,10 +962,9 @@ static const struct snd_soc_component_driver q6afe_dai_component = {
>  static void of_q6afe_parse_dai_data(struct device *dev,
>  				    struct q6afe_dai_data *data)
>  {
> -	struct device_node *node;
>  	int ret;
>  
> -	for_each_child_of_node(dev->of_node, node) {
> +	for_each_child_of_node_scoped(dev->of_node, node) {
>  		unsigned int lines[Q6AFE_MAX_MI2S_LINES];
>  		struct q6afe_dai_priv_data *priv;
>  		int id, i, num_lines;
> diff --git a/sound/soc/qcom/qdsp6/q6asm-dai.c b/sound/soc/qcom/qdsp6/q6asm-dai.c
> index a400c9a31fea..d7680dd3a3bb 100644
> --- a/sound/soc/qcom/qdsp6/q6asm-dai.c
> +++ b/sound/soc/qcom/qdsp6/q6asm-dai.c
> @@ -1236,10 +1236,8 @@ static int of_q6asm_parse_dai_data(struct device *dev,
>  {
>  	struct snd_soc_dai_driver *dai_drv;
>  	struct snd_soc_pcm_stream empty_stream;
> -	struct device_node *node;
>  	int ret, id, dir, idx = 0;
>  
> -
>  	pdata->num_dais = of_get_child_count(dev->of_node);
>  	if (!pdata->num_dais) {
>  		dev_err(dev, "No dais found in DT\n");
> @@ -1253,7 +1251,7 @@ static int of_q6asm_parse_dai_data(struct device *dev,
>  
>  	memset(&empty_stream, 0, sizeof(empty_stream));
>  
> -	for_each_child_of_node(dev->of_node, node) {
> +	for_each_child_of_node_scoped(dev->of_node, node) {
>  		ret = of_property_read_u32(node, "reg", &id);
>  		if (ret || id >= MAX_SESSIONS || id < 0) {
>  			dev_err(dev, "valid dai id not found:%d\n", ret);
> -- 
> 2.47.1
> 

-- 
With best wishes
Dmitry

Re: [PATCH v2 2/6] ASoC: aoa: Use helper function for_each_child_of_node_scoped()

[Johannes Berg]

Hi,

[you should avoid HTML]

> "simplifies the code" is no need to callof_node_put() .

Fair. Except that's not what you _actually_ changed here. Like I said,
either it's buggy before or after.

johannes

Re: [PATCH v2 2/6] ASoC: aoa: Use helper function for_each_child_of_node_scoped()

[Christophe Leroy]

Le 22/05/2025 à 07:02, Ai Chao a écrit :
> The for_each_child_of_node_scoped() helper provides a scope-based
> clean-up functionality to put the device_node automatically, and
> as such, there is no need to call of_node_put() directly.

I don't understand this explanation.

You say "no need to call of_node_put()" and the only thing you do in 
addition to changing from for_each_child_of_node() to 
for_each_child_of_node_scoped() is to _add_ a new call to of_node_put().

I would expect to see a _removal_ of some of_node_put() when I read your 
description.

Christophe

> 
> Thus, use this helper to simplify the code.
> 
> Signed-off-by: Ai Chao <aichao@kylinos.cn>
> ---
>   sound/aoa/soundbus/i2sbus/core.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/sound/aoa/soundbus/i2sbus/core.c b/sound/aoa/soundbus/i2sbus/core.c
> index ce84288168e4..20a4c5891afc 100644
> --- a/sound/aoa/soundbus/i2sbus/core.c
> +++ b/sound/aoa/soundbus/i2sbus/core.c
> @@ -207,6 +207,8 @@ static int i2sbus_add_dev(struct macio_dev *macio,
>   			}
>   		}
>   	}
> +	of_node_put(sound);
> +
>   	/* for the time being, until we can handle non-layout-id
>   	 * things in some fabric, refuse to attach if there is no
>   	 * layout-id property or we haven't been forced to attach.
> @@ -335,7 +337,6 @@ static int i2sbus_add_dev(struct macio_dev *macio,
>   
>   static int i2sbus_probe(struct macio_dev* dev, const struct of_device_id *match)
>   {
> -	struct device_node *np;
>   	int got = 0, err;
>   	struct i2sbus_control *control = NULL;
>   
> @@ -347,7 +348,7 @@ static int i2sbus_probe(struct macio_dev* dev, const struct of_device_id *match)
>   		return -ENODEV;
>   	}
>   
> -	for_each_child_of_node(dev->ofdev.dev.of_node, np) {
> +	for_each_child_of_node_scoped(dev->ofdev.dev.of_node, np) {
>   		if (of_device_is_compatible(np, "i2sbus") ||
>   		    of_device_is_compatible(np, "i2s-modem")) {
>   			got += i2sbus_add_dev(dev, control, np);

Re: [PATCH v2 2/6] ASoC: aoa: Use helper function for_each_child_of_node_scoped()

[Ai Chao]

Hi Johannes:

>> "simplifies the code" is no need to callof_node_put() .
> Fair. Except that's not what you _actually_ changed here. Like I said,
> either it's buggy before or after.
>
In the function i2sbus_probe, it not return a struct device_node, so , I 
think function for_each_child_of_node_scoped is better than 
for_each_child_of_node.

Best regards,
Ai Chao

Re: [PATCH v2 2/6] ASoC: aoa: Use helper function for_each_child_of_node_scoped()

[Johannes Berg]

On Mon, 2025-05-26 at 16:12 +0800, Ai Chao wrote:
> Hi Johannes:
> 
> > > "simplifies the code" is no need to callof_node_put() .
> > Fair. Except that's not what you _actually_ changed here. Like I said,
> > either it's buggy before or after.
> > 
> In the function i2sbus_probe, it not return a struct device_node, so , I 
> think function for_each_child_of_node_scoped is better than 
> for_each_child_of_node.

You still haven't explained why it's even correct.

johannes

Re: [PATCH v2 2/6] ASoC: aoa: Use helper function for_each_child_of_node_scoped()

[Ai Chao]

Hi Johannes:
>> Hi Johannes:
>>
>>>> "simplifies the code" is no need to callof_node_put() .
>>> Fair. Except that's not what you _actually_ changed here. Like I said,
>>> either it's buggy before or after.
>>>
>> In the function i2sbus_probe, it not return a struct device_node, so , I
>> think function for_each_child_of_node_scoped is better than
>> for_each_child_of_node.
> You still haven't explained why it's even correct.
>
> johannes

The for_each_child_of_node() function is used to iterate over all child 
nodes of a device tree node.
During each iteration, it retrieves a pointer to the child node via 
of_get_next_child() and automatically increments the node's reference 
count (of_node_get()).
Each call to of_get_next_child() increases the reference count 
(refcount) of the returned child node, ensuring that the node is not 
freed while in use.
for_each_child_of_node() increments the child node's reference count in 
each iteration but does not decrement it automatically.
If of_node_put() is not called manually, the reference count will never 
reach zero, resulting in a memory leak of the node.

Best regards,
Ai Chao

Re: [PATCH v2 2/6] ASoC: aoa: Use helper function for_each_child_of_node_scoped()

[Johannes Berg]

On Mon, 2025-05-26 at 16:20 +0800, Ai Chao wrote:
> Hi Johannes:
> > > Hi Johannes:
> > > 
> > > > > "simplifies the code" is no need to callof_node_put() .
> > > > Fair. Except that's not what you _actually_ changed here. Like I said,
> > > > either it's buggy before or after.
> > > > 
> > > In the function i2sbus_probe, it not return a struct device_node, so , I
> > > think function for_each_child_of_node_scoped is better than
> > > for_each_child_of_node.
> > You still haven't explained why it's even correct.
> > 
> > johannes
> 
> The for_each_child_of_node() function is used to iterate over all child 
> nodes of a device tree node.
> During each iteration, it retrieves a pointer to the child node via 
> of_get_next_child() and automatically increments the node's reference 
> count (of_node_get()).
> Each call to of_get_next_child() increases the reference count 
> (refcount) of the returned child node, ensuring that the node is not 
> freed while in use.
> for_each_child_of_node() increments the child node's reference count in 
> each iteration but does not decrement it automatically.
> If of_node_put() is not called manually, the reference count will never 
> reach zero, resulting in a memory leak of the node.

Yes, good! Now show that you can apply what you've learned to the
specific code (and changes) at hand.

johannes

Re: [PATCH v2 2/6] ASoC: aoa: Use helper function for_each_child_of_node_scoped()

[Ai Chao]

Hi Christophe:

>> The for_each_child_of_node_scoped() helper provides a scope-based
>> clean-up functionality to put the device_node automatically, and
>> as such, there is no need to call of_node_put() directly.
>
> I don't understand this explanation.
>
> You say "no need to call of_node_put()" and the only thing you do in 
> addition to changing from for_each_child_of_node() to 
> for_each_child_of_node_scoped() is to _add_ a new call to of_node_put().
>
> I would expect to see a _removal_ of some of_node_put() when I read 
> your description.
>
>>       }
>> +    of_node_put(sound);
>> +

The for_each_child_of_node() function is used to iterate over all child 
nodes of a device tree node.  During each iteration, it retrieves a 
pointer to the child node via of_get_next_child() and automatically 
increments the node's reference count (of_node_get()). Each call to 
of_get_next_child() increases the reference count (refcount) of the 
returned child node, ensuring that the node is not freed while in use.
for_each_child_of_node() increments the child node's reference count in 
each iteration but does not decrement it automatically.
If of_node_put() is not called manually, the reference count will never 
reach zero, resulting in a memory leak of the node.

In function i2sbus_add_dev, it used device_node out of 
for_each_child_of_node(){},  it need to add a new call to 
of_node_put(sound) to reference count.

In function i2cbus_probe, it used device_node in 
for_each_child_of_node(){}, used for_each_child_of_node_scoped() is 
better than for_each_child_of_node().

Best regards,
Ai Chao

Re: [PATCH v2 2/6] ASoC: aoa: Use helper function for_each_child_of_node_scoped()

[Dmitry Baryshkov]

On Mon, May 26, 2025 at 04:20:37PM +0800, Ai Chao wrote:
> 
> Hi Johannes:
> > > Hi Johannes:
> > > 
> > > > > "simplifies the code" is no need to callof_node_put() .
> > > > Fair. Except that's not what you _actually_ changed here. Like I said,
> > > > either it's buggy before or after.
> > > > 
> > > In the function i2sbus_probe, it not return a struct device_node, so , I
> > > think function for_each_child_of_node_scoped is better than
> > > for_each_child_of_node.
> > You still haven't explained why it's even correct.
> > 
> > johannes
> 
> The for_each_child_of_node() function is used to iterate over all child
> nodes of a device tree node.
> During each iteration, it retrieves a pointer to the child node via
> of_get_next_child() and automatically increments the node's reference count
> (of_node_get()).

This is not complete story, you missed the second part of it.

> Each call to of_get_next_child() increases the reference count (refcount) of
> the returned child node, ensuring that the node is not freed while in use.
> for_each_child_of_node() increments the child node's reference count in each
> iteration but does not decrement it automatically.
> If of_node_put() is not called manually, the reference count will never
> reach zero, resulting in a memory leak of the node.
> 
> Best regards,
> Ai Chao

-- 
With best wishes
Dmitry

Re: [PATCH v2 2/6] ASoC: aoa: Use helper function for_each_child_of_node_scoped()

[Ai Chao]

Hi Johannes:
     Thanks for your feedback.  I will drop it.

> On Mon, 2025-05-26 at 16:20 +0800, Ai Chao wrote:
>> Hi Johannes:
>>>> for_each_child_of_node.
>>> You still haven't explained why it's even correct.
>>>
>>> johannes
>> The for_each_child_of_node() function is used to iterate over all child
>> nodes of a device tree node.
>> During each iteration, it retrieves a pointer to the child node via
>> of_get_next_child() and automatically increments the node's reference
>> count (of_node_get()).
>> Each call to of_get_next_child() increases the reference count
>> (refcount) of the returned child node, ensuring that the node is not
>> freed while in use.
>> for_each_child_of_node() increments the child node's reference count in
>> each iteration but does not decrement it automatically.
>> If of_node_put() is not called manually, the reference count will never
>> reach zero, resulting in a memory leak of the node.
> Yes, good! Now show that you can apply what you've learned to the
> specific code (and changes) at hand.
>
> johannes

-- 
Best regards,
Ai Chao