When the card is registered by the machine driver, dai link components are probed after the snd_card is created. This is done in snd_soc_bind_card() which calls snd_soc_instantiate_card() to first create the snd_card and then probes the link components by calling soc_probe_link_components(). The snd_card is used by the component driver to add the kcontrols associated with dapm widgets to the card.
When the machine driver is unregistered, the snd_card is freed when the card resources are cleaned up. But the snd_card needs to be valid while unloading the topology dapm widgets in order to remove the kcontrols from the card.
Since, unloading topology is done when the component driver is removed, the link components should be removed in snd_soc_unbind_card(). This will ensure that the kcontrols are removed before the card resources are cleaned up and the snd_card itself is freed.
Signed-off-by: Ranjani Sridharan ranjani.sridharan@linux.intel.com --- sound/soc/soc-core.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c index ffd4db97a2ee..6277b2da68b7 100644 --- a/sound/soc/soc-core.c +++ b/sound/soc/soc-core.c @@ -2831,10 +2831,21 @@ EXPORT_SYMBOL_GPL(snd_soc_register_card);
static void snd_soc_unbind_card(struct snd_soc_card *card, bool unregister) { + struct snd_soc_pcm_runtime *rtd; + int order; + if (card->instantiated) { card->instantiated = false; snd_soc_dapm_shutdown(card); snd_soc_flush_all_delayed_work(card); + + /* remove all components used by DAI links on this card */ + for_each_comp_order(order) { + for_each_card_rtds(card, rtd) { + soc_remove_link_components(card, rtd, order); + } + } + soc_cleanup_card_resources(card); if (!unregister) list_add(&card->list, &unbind_card_list);