From a3375522bb5e28285cb1845ad5601bf4a581da04 Mon Sep 17 00:00:00 2001 From: Cezary Rojewski Date: Fri, 4 Apr 2025 12:16:21 +0200 Subject: ASoC: core: Complete support for card rebinding MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Since commit e894efef9ac7 ("ASoC: core: add support to card rebind") there is a support for card rebind. The support is only partial though. Let's consider the following scenarios both of which aim to enumerate a sound card: 1) snd_soc_add_component(comp1); (...) snd_soc_register_card(card1); 2) snd_soc_register_card(card1); (...) snd_soc_add_component(comp1); For the sake of simplicity, let comp1 be the last dependency needed for the card1 to enumerate. Case 1) will end up succeeding whereas 2) is a certain fail - snd_soc_bind_card() does not honor unbind_card_list so even a non-fatal return code of EPROBE_DEFER will cause the card to collapse. Given the typical usecase of platform_device serving as a card->dev and its probe() ending with: int carddev_probe(struct platform_device *pdev) { (...) return devm_snd_soc_register_card(dev, card); } failure to register card triggers device_unbind_cleanup() - really_probe() in dd.c. To allow for card registration to be deferred while being friendly towards existing users of devm_snd_soc_register_card(), add new card->devres_dev field, and devm_xxx() variants for card registration: devm_snd_soc_register_deferrable_card() (external) devm_snd_soc_bind_card() (internal) In essence, if requested, devm_snd_soc_bind_card() replaces snd_soc_bind_card(). The rebind procedure takes care of destroying old devres before attempting the new bind. This makes sure nothing is left hanging if binding fails and card becomes unbound but is still registered to the ASoC framework. To allow snd_soc_bind_card() to be reused by the deferrable friends, move 'client_mutex' locking to the function's callers and select between devm_xxx and non-devm_xxx variants of snd_soc_bind_card() based on card->devres_dev. On top of the feature, the refactoring brings two benefits: a) single lock/unlock of 'client_mutex' in snd_soc_add_component() instead of ambiguous unlock and immediate lock in snd_soc_try_rebind_card() b) all unbind_card_list manipulations done under 'client_mutex' Reviewed-by: Amadeusz Sławiński Signed-off-by: Cezary Rojewski Link: https://patch.msgid.link/20250404101622.3673850-1-cezary.rojewski@intel.com Signed-off-by: Mark Brown --- include/sound/soc.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include') diff --git a/include/sound/soc.h b/include/sound/soc.h index 952ed77b8c87..484d8b3a34f3 100644 --- a/include/sound/soc.h +++ b/include/sound/soc.h @@ -423,6 +423,7 @@ enum snd_soc_pcm_subclass { int snd_soc_register_card(struct snd_soc_card *card); void snd_soc_unregister_card(struct snd_soc_card *card); int devm_snd_soc_register_card(struct device *dev, struct snd_soc_card *card); +int devm_snd_soc_register_deferrable_card(struct device *dev, struct snd_soc_card *card); #ifdef CONFIG_PM_SLEEP int snd_soc_suspend(struct device *dev); int snd_soc_resume(struct device *dev); @@ -1087,6 +1088,7 @@ struct snd_soc_card { unsigned int fully_routed:1; unsigned int probed:1; unsigned int component_chaining:1; + struct device *devres_dev; void *drvdata; }; -- cgit v1.2.3