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Commit c0a480d1 authored by Tony Lindgren's avatar Tony Lindgren Committed by Mark Brown
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device property: Fix usecount for of_graph_get_port_parent() 



Fix inconsistent use of of_graph_get_port_parent() where
asoc_simple_card_parse_graph_dai() does of_node_get() before
calling it while other callers do not. We can fix this by
not trashing the node passed to of_graph_get_port_parent().

Let's also make sure the callers have correct refcounts and remove
related incorrect of_node_put() calls for of_for_each_phandle
as that's done by of_phandle_iterator_next() except when
we break out of the loop early.

Let's fix both issues with a single patch to avoid kobject
refcounts getting messed up more if two patches are merged
separately.

Otherwise strange issues can happen caused by memory corruption
caused by too many kobject_del() calls such as:

BUG: sleeping function called from invalid context at
kernel/locking/mutex.c:747
...
(___might_sleep)
(__mutex_lock)
(mutex_lock_nested)
(kernfs_remove)
(kobject_del)
(kobject_put)
(of_get_next_parent)
(of_graph_get_port_parent)
(asoc_simple_card_parse_graph_dai [snd_soc_simple_card_utils])
(asoc_graph_card_probe [snd_soc_audio_graph_card])

Fixes: 0ef472a9 ("of_graph: add of_graph_get_port_parent()")
Fixes: 2692c1c6 ("ASoC: add audio-graph-card support")
Fixes: 1689333f ("ASoC: simple-card-utils: add asoc_simple_card_parse_graph_dai()")
Signed-off-by: default avatarTony Lindgren <tony@atomide.com>
Reviewed-by: default avatarRob Herring <robh@kernel.org>
Tested-by: default avatarAntonio Borneo <borneo.antonio@gmail.com>
Tested-by: default avatarKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 5771a8c0

drivers/of/property.c

+15 −2
Original line number Diff line number Diff line
@@ -708,6 +708,15 @@ struct device_node *of_graph_get_port_parent(struct device_node *node) 
{

	unsigned int depth;



	if (!node)

		return NULL;



	/*

	 * Preserve usecount for passed in node as of_get_next_parent()

	 * will do of_node_put() on it.

	 */

	of_node_get(node);



	/* Walk 3 levels up only if there is 'ports' node. */

	for (depth = 3; depth && node; depth--) {

		node = of_get_next_parent(node);
@@ -728,12 +737,16 @@ EXPORT_SYMBOL(of_graph_get_port_parent); 
struct device_node *of_graph_get_remote_port_parent(

			       const struct device_node *node)

{

	struct device_node *np;

	struct device_node *np, *pp;



	/* Get remote endpoint node. */

	np = of_graph_get_remote_endpoint(node);



	return of_graph_get_port_parent(np);

	pp = of_graph_get_port_parent(np);



	of_node_put(np);



	return pp;

}

EXPORT_SYMBOL(of_graph_get_remote_port_parent);

sound/soc/generic/audio-graph-card.c

+5 −5
Original line number Diff line number Diff line
@@ -224,10 +224,12 @@ static int asoc_graph_card_parse_of(struct graph_card_data *priv) 


	of_for_each_phandle(&it, rc, node, "dais", NULL, 0) {

		ret = asoc_graph_card_dai_link_of(it.node, priv, idx++);

		if (ret < 0) {

			of_node_put(it.node);

		if (ret < 0)



			return ret;

		}

	}



	return asoc_simple_card_parse_card_name(card, NULL);

}
@@ -239,10 +241,8 @@ static int asoc_graph_get_dais_count(struct device *dev) 
	int count = 0;

	int rc;



	of_for_each_phandle(&it, rc, node, "dais", NULL, 0) {

	of_for_each_phandle(&it, rc, node, "dais", NULL, 0)

		count++;

		of_node_put(it.node);

	}



	return count;

}

sound/soc/generic/audio-graph-scu-card.c

+9 −6
Original line number Diff line number Diff line
@@ -215,7 +215,6 @@ static int asoc_graph_card_parse_of(struct graph_card_data *priv) 
		codec_ep = of_graph_get_remote_endpoint(cpu_ep);

		rcpu_ep  = of_graph_get_remote_endpoint(codec_ep);



		of_node_put(cpu_port);

		of_node_put(cpu_ep);

		of_node_put(codec_ep);

		of_node_put(rcpu_ep);
@@ -232,9 +231,11 @@ static int asoc_graph_card_parse_of(struct graph_card_data *priv) 


		ret = asoc_simple_card_parse_daifmt(dev, cpu_ep, codec_ep,

							    NULL, &daifmt);

		if (ret < 0)

		if (ret < 0) {

			of_node_put(cpu_port);

			goto parse_of_err;

		}

	}



	dai_idx = 0;

	codec_port_old = NULL;
@@ -250,7 +251,6 @@ static int asoc_graph_card_parse_of(struct graph_card_data *priv) 
			codec_ep = of_graph_get_remote_endpoint(cpu_ep);

			codec_port = of_graph_get_port_parent(codec_ep);



			of_node_put(cpu_port);

			of_node_put(cpu_ep);

			of_node_put(codec_ep);

			of_node_put(codec_port);
@@ -266,16 +266,20 @@ static int asoc_graph_card_parse_of(struct graph_card_data *priv) 


				/* Back-End (= Codec) */

				ret = asoc_graph_card_dai_link_of(codec_ep, priv, daifmt, dai_idx++, 0);

				if (ret < 0)

				if (ret < 0) {

					of_node_put(cpu_port);

					goto parse_of_err;

				}

			} else {

				/* Front-End (= CPU) */

				ret = asoc_graph_card_dai_link_of(cpu_ep, priv, daifmt, dai_idx++, 1);

				if (ret < 0)

				if (ret < 0) {

					of_node_put(cpu_port);

					goto parse_of_err;

				}

			}

		}

	}



	ret = asoc_simple_card_parse_card_name(card, NULL);

	if (ret)
@@ -306,7 +310,6 @@ static int asoc_graph_get_dais_count(struct device *dev) 
		codec_ep = of_graph_get_remote_endpoint(cpu_ep);

		codec_port = of_graph_get_port_parent(codec_ep);



		of_node_put(cpu_port);

		of_node_put(cpu_ep);

		of_node_put(codec_ep);

		of_node_put(codec_port);

sound/soc/generic/simple-card-utils.c

+3 −5
Original line number Diff line number Diff line
@@ -263,6 +263,9 @@ static int asoc_simple_card_get_dai_id(struct device_node *ep) 
			id = i;

		i++;

	}



	of_node_put(node);



	if (id < 0)

		return -ENODEV;
@@ -282,11 +285,6 @@ int asoc_simple_card_parse_graph_dai(struct device_node *ep, 
	if (!dai_name)

		return 0;



	/*

	 * of_graph_get_port_parent() will call

	 * of_node_put(). So, call of_node_get() here

	 */

	of_node_get(ep);

	node = of_graph_get_port_parent(ep);



	/* Get dai->name */

sound/soc/soc-core.c

+2 −0
Original line number Diff line number Diff line
@@ -4113,6 +4113,8 @@ int snd_soc_get_dai_id(struct device_node *ep) 
	}

	mutex_unlock(&client_mutex);



	of_node_put(node);



	return ret;

}

EXPORT_SYMBOL_GPL(snd_soc_get_dai_id);