[PATCH v2] ASoC: soc-core.c: Prefer to return dai->driver->name in snd_soc_dai_name_get()

From: Chancel Liu
Date: Wed Jan 31 2024 - 05:27:38 EST


ASoC machine driver can use snd_soc_{of_}get_dlc() (A) to get DAI name
for dlc (snd_soc_dai_link_component). In this function call
dlc->dai_name is parsed via snd_soc_dai_name_get() (B).

(A) int snd_soc_get_dlc(...)
{
...
(B) dlc->dai_name = snd_soc_dai_name_get(dai);
...
}

(B) has a priority to return dai->name as dlc->dai_name. In most cases
card can probe successfully. However it has an issue that ASoC tries to
rebind card. Here is a simplified flow for example:

| a) Card probes successfully at first
| b) One of the component bound to this card is removed for some
| reason the component->dev is released
| c) That component is re-registered
v d) ASoC calls snd_soc_try_rebind_card()

a) points dlc->dai_name to dai->name. b) releases all resource of the
old DAI. c) creates new DAI structure. In result d) can not use
dlc->dai_name to add new created DAI.

So it's reasonable that prefer to return dai->driver->name in
snd_soc_dai_name_get() because dai->driver is a pre-defined global
variable. Also update snd_soc_is_matching_dai() for alignment.

Signed-off-by: Chancel Liu <chancel.liu@xxxxxxx>
---
sound/soc/soc-core.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index 516350533e73..847f92721fdb 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -283,13 +283,13 @@ static int snd_soc_is_matching_dai(const struct snd_soc_dai_link_component *dlc,

/* see snd_soc_dai_name_get() */

- if (strcmp(dlc->dai_name, dai->name) == 0)
- return 1;
-
if (dai->driver->name &&
strcmp(dai->driver->name, dlc->dai_name) == 0)
return 1;

+ if (strcmp(dlc->dai_name, dai->name) == 0)
+ return 1;
+
if (dai->component->name &&
strcmp(dlc->dai_name, dai->component->name) == 0)
return 1;
@@ -300,12 +300,12 @@ static int snd_soc_is_matching_dai(const struct snd_soc_dai_link_component *dlc,
const char *snd_soc_dai_name_get(struct snd_soc_dai *dai)
{
/* see snd_soc_is_matching_dai() */
- if (dai->name)
- return dai->name;
-
if (dai->driver->name)
return dai->driver->name;

+ if (dai->name)
+ return dai->name;
+
if (dai->component->name)
return dai->component->name;

--
2.43.0