[PATCH v2 1/3] ASoC: fix use of of_node_put() in of_for_each_phandle() loops

From: Antonio Borneo
Date: Thu Jul 27 2017 - 19:27:20 EST


From: Antonio Borneo <borneo.antonio@xxxxxxxxx>

On Hikey target board, enabling CONFIG_OF_DYNAMIC triggers several
errors at kernel boot, like the following one
OF: ERROR: Bad of_node_put() on /soc/i2s@f7118000/ports/port@0
each followed by stack dump.

Each iteration of of_for_each_phandle(){} already provides the
needed of_node_put(); adding one more in the body of the loop
triggers the error.
Fixed by removing the wrong of_node_put(), but adding it when the
loop is break out.

Tested with kernel v4.13-rc2 with hikey_defconfig taken from
https://git.linaro.org/people/john.stultz/android-dev.git
branch dev/hikey-mainline-WIP

This fixes commit 2692c1c63c29 ("ASoC: add audio-graph-card
support").

Signed-off-by: Antonio Borneo <borneo.antonio@xxxxxxxxx>
---
To: Liam Girdwood <lgirdwood@xxxxxxxxx>
To: Mark Brown <broonie@xxxxxxxxxx>
To: Jaroslav Kysela <perex@xxxxxxxx>
To: Takashi Iwai <tiwai@xxxxxxxx>
To: alsa-devel@xxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: Wei Xu <xuwei5@xxxxxxxxxxxxx>
Cc: John Stultz <john.stultz@xxxxxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>
---
sound/soc/generic/audio-graph-card.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/sound/soc/generic/audio-graph-card.c b/sound/soc/generic/audio-graph-card.c
index 105ec3a..20c2029 100644
--- a/sound/soc/generic/audio-graph-card.c
+++ b/sound/soc/generic/audio-graph-card.c
@@ -224,9 +224,10 @@ 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++);
- of_node_put(it.node);
- if (ret < 0)
+ if (ret < 0) {
+ of_node_put(it.node);
return ret;
+ }
}

return asoc_simple_card_parse_card_name(card, NULL);
@@ -239,10 +240,8 @@ 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;
}
--
1.9.1