Commit c0a480d1 authored by Tony Lindgren's avatar Tony Lindgren Committed by Mark Brown

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
......@@ -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);
......
......@@ -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;
}
......
......@@ -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);
......
......@@ -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 */
......
......@@ -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);
......
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