ALSA: pcm: Don't call register and disconnect callbacks for internal PCM (8b645e4a) · Commits · 戴 / test

The internal PCM (aka DPCM backend PCM) doesn't need any registration procedure, thus currently we bail out immediately at dev_register callback. Similarly, its counterpart, dev_disconnect callback, is superfluous for the internal PCM. For simplifying and avoiding the conflicting disconnect call for internal PCM objects, this patch drops dev_register and dev_disconnect callbacks for the internal ops. The only uncertain thing by this action is whether skipping the PCM state change to SNDRV_PCM_STATE_DISCONNECT for the internal PCM is mandatory. Looking through the current implementations, this doesn't look so, hence dropping the whole dev_disconnect would make more sense. Tested-by:

Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by:

Takashi Iwai <tiwai@suse.de>

sound/core/pcm.c

+8 −8

Original line number	Diff line number	Diff line
		@@ -775,6 +775,9 @@ static int _snd_pcm_new(struct snd_card card, const char id, int device,
		.dev_register = snd_pcm_dev_register,
		.dev_disconnect = snd_pcm_dev_disconnect,
		};
		static struct snd_device_ops internal_ops = {
		.dev_free = snd_pcm_dev_free,
		};

		if (snd_BUG_ON(!card))
		return -ENXIO;
		@@ -801,7 +804,8 @@ static int _snd_pcm_new(struct snd_card card, const char id, int device,
		if (err < 0)
		goto free_pcm;

		err = snd_device_new(card, SNDRV_DEV_PCM, pcm, &ops);
		err = snd_device_new(card, SNDRV_DEV_PCM, pcm,
		internal ? &internal_ops : &ops);
		if (err < 0)
		goto free_pcm;

		@@ -1099,8 +1103,6 @@ static int snd_pcm_dev_register(struct snd_device *device)
		if (snd_BUG_ON(!device \|\| !device->device_data))
		return -ENXIO;
		pcm = device->device_data;
		if (pcm->internal)
		return 0;

		mutex_lock(&register_mutex);
		err = snd_pcm_add(pcm);
		@@ -1159,11 +1161,9 @@ static int snd_pcm_dev_disconnect(struct snd_device *device)
		snd_pcm_stream_unlock_irq(substream);
		}
		}
		if (!pcm->internal) {

		pcm_call_notify(pcm, n_disconnect);
		}
		for (cidx = 0; cidx < 2; cidx++) {
		if (!pcm->internal)
		snd_unregister_device(&pcm->streams[cidx].dev);
		free_chmap(&pcm->streams[cidx]);
		}

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