Hi Takashi
This is reply for old email. This thread talked about hot-unplug during playback.
aplay xxx & echo xxx > /sys/bus/platform/drivers/xxx/unbind
We need to stop all components on framework level. And you kindly created its prototype solution.
diff --git a/include/sound/core.h b/include/sound/core.h index 4104a9d1001f..5f181b875c2f 100644 --- a/include/sound/core.h +++ b/include/sound/core.h @@ -133,6 +133,7 @@ struct snd_card { struct device card_dev; /* cardX object for sysfs */ const struct attribute_group *dev_groups[4]; /* assigned sysfs attr */ bool registered; /* card_dev is registered? */
- wait_queue_head_t remove_sleep;
#ifdef CONFIG_PM unsigned int power_state; /* power state */ @@ -240,6 +241,7 @@ int snd_card_new(struct device *parent, int idx, const char *xid, struct snd_card **card_ret);
int snd_card_disconnect(struct snd_card *card); +void snd_card_disconnect_sync(struct snd_card *card); int snd_card_free(struct snd_card *card); int snd_card_free_when_closed(struct snd_card *card); void snd_card_set_id(struct snd_card *card, const char *id); diff --git a/sound/core/init.c b/sound/core/init.c index 32ebe2f6bc59..5cde6cc0d867 100644 --- a/sound/core/init.c +++ b/sound/core/init.c @@ -255,6 +255,7 @@ int snd_card_new(struct device *parent, int idx, const char *xid, #ifdef CONFIG_PM init_waitqueue_head(&card->power_sleep); #endif
init_waitqueue_head(&card->remove_sleep);
device_initialize(&card->card_dev); card->card_dev.parent = parent;
@@ -452,6 +453,17 @@ int snd_card_disconnect(struct snd_card *card) } EXPORT_SYMBOL(snd_card_disconnect);
+void snd_card_disconnect_sync(struct snd_card *card) +{
- snd_card_disconnect(card);
- spin_lock_irq(&card->files_lock);
- wait_event_lock_irq(card->remove_sleep,
list_empty(&card->files_list),card->files_lock);- spin_unlock_irq(&card->files_lock);
+} +EXPORT_SYMBOL_GPL(snd_card_disconnect_sync);
static int snd_card_do_free(struct snd_card *card) { #if IS_ENABLED(CONFIG_SND_MIXER_OSS) @@ -957,6 +969,8 @@ int snd_card_file_remove(struct snd_card *card, struct file *file) break; } }
- if (list_empty(&card->files_list))
wake_up_all(&card->remove_sleep);
I tried this patch, and noticed 2 issues (at this point). I think below thing happen on this process.
1) snd_pcm_dev_disconnect() is called - status will be SNDRV_PCM_STATE_DISCONNECTED;
2) snd_pcm_release() is called - snd_pcm_release_substream() is called - snd_pcm_drop() is called
snd_pcm_drop() will call snd_pcm_stop(), and it stops each driver. This is needed. The issue will be happen if 1) happen before 2) (I think)
1st issue is
snd_pcm_drop() has this check
if (runtime->status->state == SNDRV_PCM_STATE_OPEN || runtime->status->state == SNDRV_PCM_STATE_DISCONNECTED) return -EBADFD;
if 1) happen before 2), snd_pcm_drop() returns immediately, and doesn't call snd_pcm_stop().
I modified this as quick-hack locally. Then, 2nd issue happen on snd_pcm_stop(). it will call snd_pcm_do_stop(), and it has
if (substream->runtime->trigger_master == substream && snd_pcm_running(substream)) substream->ops->trigger(substream, SNDRV_PCM_TRIGGER_STOP);
Here, trigger isn't called, because snd_pcm_running() is 0. This is because status is SNDRV_PCM_STATE_DISCONNECTED if 1) happen before 2).
I don't know detail of these status magic, but do you have some idea/solution ?
Best regards --- Kuninori Morimoto