From: Kuninori Morimoto <[email protected]>

[ Upstream commit 20d9fdee72dfaa1fa7588c7a846283bd740e7157 ]

commit 25612477d20b52 ("ASoC: soc-dai: set dai_link dpcm_ flags with a helper")
added snd_soc_dai_link_set_capabilities().
But it is using snd_soc_find_dai() (A) which is required client_mutex (B).
And client_mutex is soc-core.c local.

        struct snd_soc_dai *snd_soc_find_dai(xxx)
        {
                ...
(B)             lockdep_assert_held(&client_mutex);
                ...
        }

        void snd_soc_dai_link_set_capabilities(xxx)
        {
                ...
                for_each_pcm_streams(direction) {
                        ...
                        for_each_link_cpus(dai_link, i, cpu) {
(A)                             dai = snd_soc_find_dai(cpu);
                                ...
                        }
                        ...
                        for_each_link_codecs(dai_link, i, codec) {
(A)                             dai = snd_soc_find_dai(codec);
                                ...
                        }
                }
                ...
        }

Because of these background, we will get WARNING if .config has CONFIG_LOCKDEP.

        WARNING: CPU: 2 PID: 53 at sound/soc/soc-core.c:814 
snd_soc_find_dai+0xf8/0x100
        CPU: 2 PID: 53 Comm: kworker/2:1 Not tainted 5.7.0-rc1+ #328
        Hardware name: Renesas H3ULCB Kingfisher board based on r8a77951 (DT)
        Workqueue: events deferred_probe_work_func
        pstate: 60000005 (nZCv daif -PAN -UAO)
        pc : snd_soc_find_dai+0xf8/0x100
        lr : snd_soc_find_dai+0xf4/0x100
        ...
        Call trace:
         snd_soc_find_dai+0xf8/0x100
         snd_soc_dai_link_set_capabilities+0xa0/0x16c
         graph_dai_link_of_dpcm+0x390/0x3c0
         graph_for_each_link+0x134/0x200
         graph_probe+0x144/0x230
         platform_drv_probe+0x5c/0xb0
         really_probe+0xe4/0x430
         driver_probe_device+0x60/0xf4

snd_soc_find_dai() will be used from (X) CPU/Codec/Platform driver with
mutex lock, and (Y) Card driver without mutex lock.
This snd_soc_dai_link_set_capabilities() is for Card driver,
this means called without mutex.
This patch adds snd_soc_find_dai_with_mutex() to solve it.

Fixes: 25612477d20b52 ("ASoC: soc-dai: set dai_link dpcm_ flags with a helper")
Signed-off-by: Kuninori Morimoto <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mark Brown <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
---
 include/sound/soc.h  |  2 ++
 sound/soc/soc-core.c | 13 +++++++++++++
 sound/soc/soc-dai.c  |  4 ++--
 3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/include/sound/soc.h b/include/sound/soc.h
index 3ce7f0f5aa929..bc6ecb10c7649 100644
--- a/include/sound/soc.h
+++ b/include/sound/soc.h
@@ -1373,6 +1373,8 @@ void snd_soc_unregister_dai(struct snd_soc_dai *dai);
 
 struct snd_soc_dai *snd_soc_find_dai(
        const struct snd_soc_dai_link_component *dlc);
+struct snd_soc_dai *snd_soc_find_dai_with_mutex(
+       const struct snd_soc_dai_link_component *dlc);
 
 #include <sound/soc-dai.h>
 
diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index f1d641cd48da9..20ca1d38b4b87 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -834,6 +834,19 @@ struct snd_soc_dai *snd_soc_find_dai(
 }
 EXPORT_SYMBOL_GPL(snd_soc_find_dai);
 
+struct snd_soc_dai *snd_soc_find_dai_with_mutex(
+       const struct snd_soc_dai_link_component *dlc)
+{
+       struct snd_soc_dai *dai;
+
+       mutex_lock(&client_mutex);
+       dai = snd_soc_find_dai(dlc);
+       mutex_unlock(&client_mutex);
+
+       return dai;
+}
+EXPORT_SYMBOL_GPL(snd_soc_find_dai_with_mutex);
+
 static int soc_dai_link_sanity_check(struct snd_soc_card *card,
                                     struct snd_soc_dai_link *link)
 {
diff --git a/sound/soc/soc-dai.c b/sound/soc/soc-dai.c
index cecbbed2de9d5..0e04ad7689cd9 100644
--- a/sound/soc/soc-dai.c
+++ b/sound/soc/soc-dai.c
@@ -410,14 +410,14 @@ void snd_soc_dai_link_set_capabilities(struct 
snd_soc_dai_link *dai_link)
                supported_codec = false;
 
                for_each_link_cpus(dai_link, i, cpu) {
-                       dai = snd_soc_find_dai(cpu);
+                       dai = snd_soc_find_dai_with_mutex(cpu);
                        if (dai && snd_soc_dai_stream_valid(dai, direction)) {
                                supported_cpu = true;
                                break;
                        }
                }
                for_each_link_codecs(dai_link, i, codec) {
-                       dai = snd_soc_find_dai(codec);
+                       dai = snd_soc_find_dai_with_mutex(codec);
                        if (dai && snd_soc_dai_stream_valid(dai, direction)) {
                                supported_codec = true;
                                break;
-- 
2.25.1



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