ASoC: core: Exit all links before removing their components

Flows leading to link->init() and link->exit() are not symmetric.
Currently the relevant part of card probe sequence goes as:

	for_each_card_rtds(card, rtd)
		for_each_rtd_components(rtd, i, component)
			component->probe()
	for_each_card_rtds(card, rtd)
		for_each_rtd_dais(rtd, i, dai)
			dai->probe()
	for_each_card_rtds(card, rtd)
		rtd->init()

On the other side, equivalent remove sequence goes as:

	for_each_card_rtds(card, rtd)
		for_each_rtd_dais(rtd, i, dai)
			dai->remove()
	for_each_card_rtds(card, rtd)
		for_each_rtd_components(rtd, i, component)
			component->remove()
	for_each_card_rtds(card, rtd)
		rtd->exit()

what can lead to errors as link->exit() may still operate on resources
owned by its components despite the probability of them being freed
during the component->remove().

This change modifies the remove sequence to:

	for_each_card_rtds(card, rtd)
		rtd->exit()
	for_each_card_rtds(card, rtd)
		for_each_rtd_dais(rtd, i, dai)
			dai->remove()
	for_each_card_rtds(card, rtd)
		for_each_rtd_components(rtd, i, component)
			component->remove()

so code found in link->exit() is safe to touch any component stuff as
component->remove() has not been called yet.

Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Reviewed-by: Amadeusz Sławiński <amadeuszx.slawinski@linux.intel.com>
Link: https://lore.kernel.org/r/20221027085840.1562698-1-cezary.rojewski@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index ec554c3..d8b092f 100644 (file)
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -939,9 +939,6 @@ void snd_soc_remove_pcm_runtime(struct snd_soc_card *card,
 {
        lockdep_assert_held(&client_mutex);
 
-       /* release machine specific resources */
-       snd_soc_link_exit(rtd);
-
        /*
         * Notify the machine driver for extra destruction
         */
@@ -1890,6 +1887,9 @@ static void soc_cleanup_card_resources(struct snd_soc_card *card)
 
        snd_soc_dapm_shutdown(card);
 
+       /* release machine specific resources */
+       for_each_card_rtds(card, rtd)
+               snd_soc_link_exit(rtd);
        /* remove and free each DAI */
        soc_remove_link_dais(card);
        soc_remove_link_components(card);