Kernel crashes when an ASoC component rebinding. The dai_link->platforms has been reset to NULL by soc_cleanup_platform() in soc_cleanup_card_resources() when un-registering component. However, it has no chance to re-allocate the dai_link->platforms when registering the component again. Move the DAI pre-links initiation from snd_soc_register_card() to snd_soc_instantiate_card() to make sure all DAI pre-links get initiated when component rebinding. As an example, by using the following commands: - echo -n max98357a > /sys/bus/platform/drivers/max98357a/unbind - echo -n max98357a > /sys/bus/platform/drivers/max98357a/bind Got the error message: "Unable to handle kernel NULL pointer dereference at virtual address". The call trace: snd_soc_is_matching_component+0x30/0x6c soc_bind_dai_link+0x16c/0x240 snd_soc_bind_card+0x1e4/0xb10 snd_soc_add_component+0x270/0x300 snd_soc_register_component+0x54/0x6c Signed-off-by: Tzung-Bi Shih <tzungbi@xxxxxxxxxx> --- Changes from v1 (https://patchwork.kernel.org/patch/10968311/): - reserve original logic as much as possible - only acquire client_mutex - do not call soc_cleanup_card_resources() if soc_init_dai_link() returns fail, in the case some context (e.g. card->dapm) may have not initialized yet Difference from original logic: - soc_init_dai_link() would be called several times (e.g. -EPROBE_DEFER) sound/soc/soc-core.c | 27 ++++++++++----------------- 1 file changed, 10 insertions(+), 17 deletions(-) diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c index 7abb017a83f3..9191d2bec489 100644 --- a/sound/soc/soc-core.c +++ b/sound/soc/soc-core.c @@ -2070,6 +2070,16 @@ static int snd_soc_instantiate_card(struct snd_soc_card *card) int ret, i, order; mutex_lock(&client_mutex); + for_each_card_prelinks(card, i, dai_link) { + ret = soc_init_dai_link(card, dai_link); + if (ret) { + soc_cleanup_platform(card); + dev_err(card->dev, "ASoC: failed to init link %s: %d\n", + dai_link->name, ret); + mutex_unlock(&client_mutex); + return ret; + } + } mutex_lock_nested(&card->mutex, SND_SOC_CARD_CLASS_INIT); card->dapm.bias_level = SND_SOC_BIAS_OFF; @@ -2794,26 +2804,9 @@ static int snd_soc_bind_card(struct snd_soc_card *card) */ int snd_soc_register_card(struct snd_soc_card *card) { - int i, ret; - struct snd_soc_dai_link *link; - if (!card->name || !card->dev) return -EINVAL; - mutex_lock(&client_mutex); - for_each_card_prelinks(card, i, link) { - - ret = soc_init_dai_link(card, link); - if (ret) { - soc_cleanup_platform(card); - dev_err(card->dev, "ASoC: failed to init link %s\n", - link->name); - mutex_unlock(&client_mutex); - return ret; - } - } - mutex_unlock(&client_mutex); - dev_set_drvdata(card->dev, card); snd_soc_initialize_card_lists(card); -- 2.22.0.rc1.311.g5d7573a151-goog _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx https://mailman.alsa-project.org/mailman/listinfo/alsa-devel
