Hi Jon
> I have been looking at this again recently. I see this issue occurring
> all the time when the sound drivers are built as kernel modules and
> probing the sound card is deferred until the codec driver has been loaded.
>
> Commit daecf46ee0e5 ("ASoC: soc-core: use snd_soc_dai_link_component for
> platform") appears to introduce the problem because now we allocate the
> 'snd_soc_dai_link_component' structure for the platform we attempt to
> register the soundcard but we never clear the freed pointer on failure.
> Therefore, we only actually allocate it the first time. There is no easy
> way to clear this pointer for the memory allocated because this is done
> before the dai-links have been added to the list of dai-links for the
> soundcard.
>
> I don't see an easy solution that will be 100% robust unless you do opt
> for copying all the dai-link info from the platform (but this is
> probably not a trivial fix).
>
> Do you envision a fix any time soon, or should we be updating all the
> machine drivers to populate the platform snd_soc_dai_link_component so
> that it is handled by the machine drivers are not the core?
Thank you for pointing it.
Indeed it is mess.
I think coping info is nice idea,
but it is not easy so far, and it uses much memory...
I didn't test this, but can below patch solve your issue ?
I think same issue happen on codec side too, so it cares it too.
---------------
diff --git a/include/sound/soc.h b/include/sound/soc.h
index 8ec1de8..49ac5a8 100644
--- a/include/sound/soc.h
+++ b/include/sound/soc.h
@@ -985,6 +985,10 @@ struct snd_soc_dai_link {
/* Do not create a PCM for this DAI link (Backend link) */
unsigned int ignore:1;
+ /* allocated dai_link_comonent. These should be removed in the future */
+ unsigned int allocated_platform:1;
+ unsigned int allocated_codecs:1;
+
struct list_head list; /* DAI link list of the soc card */
struct snd_soc_dobj dobj; /* For topology */
};
diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index 0462b3e..49ccea3 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -1023,6 +1023,25 @@ static void soc_remove_dai_links(struct snd_soc_card *card)
}
}
+static void snd_soc_init_dai_link_component(struct snd_soc_card *card)
+{
+ struct snd_soc_dai_link *dai_link;
+ int i;
+
+ /*
+ * FIXME
+ *
+ * this function should be removed in the future
+ */
+ for_each_card_prelinks(card, i, dai_link) {
+ /* see snd_soc_init_platform */
+ if (dai_link->allocated_platform)
+ dai_link->platform = NULL;
+ if (dai_link->allocated_codecs)
+ dai_link->codecs = NULL;
+ }
+}
+
static int snd_soc_init_platform(struct snd_soc_card *card,
struct snd_soc_dai_link *dai_link)
{
@@ -1042,6 +1061,8 @@ static int snd_soc_init_platform(struct snd_soc_card *card,
return -ENOMEM;
dai_link->platform = platform;
+ dai_link->allocated_platform = 1;
+
platform->name = dai_link->platform_name;
platform->of_node = dai_link->platform_of_node;
platform->dai_name = NULL;
@@ -1069,6 +1090,8 @@ static int snd_soc_init_multicodec(struct snd_soc_card *card,
if (!dai_link->codecs)
return -ENOMEM;
+ dai_link->allocated_codecs = 1;
+
dai_link->codecs[0].name = dai_link->codec_name;
dai_link->codecs[0].of_node = dai_link->codec_of_node;
dai_link->codecs[0].dai_name = dai_link->codec_dai_name;
@@ -2739,6 +2762,8 @@ int snd_soc_register_card(struct snd_soc_card *card)
if (!card->name || !card->dev)
return -EINVAL;
+ snd_soc_init_dai_link_component(card);
+
for_each_card_prelinks(card, i, link) {
ret = soc_init_dai_link(card, link);
---------------
Best regards
---
Kuninori Morimoto
