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author | Tony Lindgren <tony@atomide.com> | 2017-07-28 10:23:15 +0200 |
---|---|---|
committer | Mark Brown <broonie@kernel.org> | 2017-08-01 16:15:42 +0200 |
commit | c0a480d1acf7dc184f9f3e7cf724483b0d28dc2e (patch) | |
tree | 0c4d178bc64d97ba035fa18a91ad519f2c670717 /drivers/of | |
parent | Linux v4.13-rc1 (diff) | |
download | linux-c0a480d1acf7dc184f9f3e7cf724483b0d28dc2e.tar.xz linux-c0a480d1acf7dc184f9f3e7cf724483b0d28dc2e.zip |
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: 0ef472a973eb ("of_graph: add of_graph_get_port_parent()")
Fixes: 2692c1c63c29 ("ASoC: add audio-graph-card support")
Fixes: 1689333f8311 ("ASoC: simple-card-utils: add asoc_simple_card_parse_graph_dai()")
Signed-off-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Tested-by: Antonio Borneo <borneo.antonio@gmail.com>
Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/of')
-rw-r--r-- | drivers/of/property.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/drivers/of/property.c b/drivers/of/property.c index eda50b4be934..067f9fab7b77 100644 --- a/drivers/of/property.c +++ b/drivers/of/property.c @@ -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); |