ALSA: hda - Make converter setups sticky

So far, we reset the converter setups like the stream-tag, the
channel-id and format-id in prepare callbacks, and clear them in
cleanup callbacks. This often causes a silence of the digital
receiver for a couple of seconds.

This patch tries to delay the converter setup changes as much as
possible. The converter setups are cached and aren't reset as long
as the same values are used. At suspend/resume, they are cleared
to be recovered properly, too.

Signed-off-by: Takashi Iwai <[e-mail]>

sound/pci/hda/hda_codec.c

···
 }
 
 /*
+ * audio-converter setup caches
+ */
+struct hda_cvt_setup {
+	hda_nid_t nid;
+	u8 stream_tag;
+	u8 channel_id;
+	u16 format_id;
+	unsigned char active;	/* cvt is currently used */
+	unsigned char dirty;	/* setups should be cleared */
+};
+
+/* get or create a cache entry for the given audio converter NID */
+static struct hda_cvt_setup *
+get_hda_cvt_setup(struct hda_codec *codec, hda_nid_t nid)
+{
+	struct hda_cvt_setup *p;
+	int i;
+
+	for (i = 0; i < codec->cvt_setups.used; i++) {
+		p = snd_array_elem(&codec->cvt_setups, i);
+		if (p->nid == nid)
+			return p;
+	}
+	p = snd_array_new(&codec->cvt_setups);
+	if (p)
+		p->nid = nid;
+	return p;
+}
+
+/*
  * codec destructor
  */
 static void snd_hda_codec_free(struct hda_codec *codec)
···
 	codec->addr = codec_addr;
 	mutex_init(&codec->spdif_mutex);
 	mutex_init(&codec->control_mutex);
+	mutex_init(&codec->prepare_mutex);
 	init_hda_cache(&codec->amp_cache, sizeof(struct hda_amp_info));
 	init_hda_cache(&codec->cmd_cache, sizeof(struct hda_cache_head));
 	snd_array_init(&codec->mixers, sizeof(struct hda_nid_item), 32);
 	snd_array_init(&codec->nids, sizeof(struct hda_nid_item), 32);
 	snd_array_init(&codec->init_pins, sizeof(struct hda_pincfg), 16);
 	snd_array_init(&codec->driver_pins, sizeof(struct hda_pincfg), 16);
+	snd_array_init(&codec->cvt_setups, sizeof(struct hda_cvt_setup), 8);
 	if (codec->bus->modelname) {
 		codec->modelname = kstrdup(codec->bus->modelname, GFP_KERNEL);
 		if (!codec->modelname) {
···
 				u32 stream_tag,
 				int channel_id, int format)
 {
+	struct hda_cvt_setup *p;
+	unsigned int oldval, newval;
+	int i;
+
 	if (!nid)
 		return;
 
 	snd_printdd("hda_codec_setup_stream: "
 		    "NID=0x%x, stream=0x%x, channel=%d, format=0x%x\n",
 		    nid, stream_tag, channel_id, format);
-	snd_hda_codec_write(codec, nid, 0, AC_VERB_SET_CHANNEL_STREAMID,
-			    (stream_tag << 4) | channel_id);
-	msleep(1);
-	snd_hda_codec_write(codec, nid, 0, AC_VERB_SET_STREAM_FORMAT, format);
+	p = get_hda_cvt_setup(codec, nid);
+	if (!p)
+		return;
+	/* update the stream-id if changed */
+	if (p->stream_tag != stream_tag || p->channel_id != channel_id) {
+		oldval = snd_hda_codec_read(codec, nid, 0, AC_VERB_GET_CONV, 0);
+		newval = (stream_tag << 4) | channel_id;
+		if (oldval != newval)
+			snd_hda_codec_write(codec, nid, 0,
+					    AC_VERB_SET_CHANNEL_STREAMID,
+					    newval);
+		p->stream_tag = stream_tag;
+		p->channel_id = channel_id;
+	}
+	/* update the format-id if changed */
+	if (p->format_id != format) {
+		oldval = snd_hda_codec_read(codec, nid, 0,
+					    AC_VERB_GET_STREAM_FORMAT, 0);
+		if (oldval != format) {
+			msleep(1);
+			snd_hda_codec_write(codec, nid, 0,
+					    AC_VERB_SET_STREAM_FORMAT,
+					    format);
+		}
+		p->format_id = format;
+	}
+	p->active = 1;
+	p->dirty = 0;
+
+	/* make other inactive cvts with the same stream-tag dirty */
+	for (i = 0; i < codec->cvt_setups.used; i++) {
+		p = snd_array_elem(&codec->cvt_setups, i);
+		if (!p->active && p->stream_tag == stream_tag)
+			p->dirty = 1;
+	}
 }
 EXPORT_SYMBOL_HDA(snd_hda_codec_setup_stream);
 
···
  */
 void snd_hda_codec_cleanup_stream(struct hda_codec *codec, hda_nid_t nid)
 {
+	struct hda_cvt_setup *p;
+
 	if (!nid)
 		return;
 
 	snd_printdd("hda_codec_cleanup_stream: NID=0x%x\n", nid);
-	snd_hda_codec_write(codec, nid, 0, AC_VERB_SET_CHANNEL_STREAMID, 0);
-#if 0 /* keep the format */
-	msleep(1);
-	snd_hda_codec_write(codec, nid, 0, AC_VERB_SET_STREAM_FORMAT, 0);
-#endif
+	/* here we just clear the active flag; actual clean-ups will be done
+	 * in purify_inactive_streams()
+	 */
+	p = get_hda_cvt_setup(codec, nid);
+	if (p)
+		p->active = 0;
 }
 EXPORT_SYMBOL_HDA(snd_hda_codec_cleanup_stream);
+
+static void really_cleanup_stream(struct hda_codec *codec,
+				  struct hda_cvt_setup *q)
+{
+	hda_nid_t nid = q->nid;
+	snd_hda_codec_write(codec, nid, 0, AC_VERB_SET_CHANNEL_STREAMID, 0);
+	snd_hda_codec_write(codec, nid, 0, AC_VERB_SET_STREAM_FORMAT, 0);
+	memset(q, 0, sizeof(*q));
+	q->nid = nid;
+}
+
+/* clean up the all conflicting obsolete streams */
+static void purify_inactive_streams(struct hda_codec *codec)
+{
+	int i;
+
+	for (i = 0; i < codec->cvt_setups.used; i++) {
+		struct hda_cvt_setup *p = snd_array_elem(&codec->cvt_setups, i);
+		if (p->dirty)
+			really_cleanup_stream(codec, p);
+	}
+}
+
+/* clean up all streams; called from suspend */
+static void hda_cleanup_all_streams(struct hda_codec *codec)
+{
+	int i;
+
+	for (i = 0; i < codec->cvt_setups.used; i++) {
+		struct hda_cvt_setup *p = snd_array_elem(&codec->cvt_setups, i);
+		if (p->stream_tag)
+			really_cleanup_stream(codec, p);
+	}
+}
 
 /*
  * amp access functions
···
 {
 	if (codec->patch_ops.suspend)
 		codec->patch_ops.suspend(codec, PMSG_SUSPEND);
+	hda_cleanup_all_streams(codec);
 	hda_set_power_state(codec,
 			    codec->afg ? codec->afg : codec->mfg,
 			    AC_PWRST_D3);
···
 	}
 	return 0;
 }
+
+/*
+ * codec prepare/cleanup entries
+ */
+int snd_hda_codec_prepare(struct hda_codec *codec,
+			  struct hda_pcm_stream *hinfo,
+			  unsigned int stream,
+			  unsigned int format,
+			  struct snd_pcm_substream *substream)
+{
+	int ret;
+	mutex_lock(&codec->prepare_mutex);
+	ret = hinfo->ops.prepare(hinfo, codec, stream, format, substream);
+	if (ret >= 0)
+		purify_inactive_streams(codec);
+	mutex_unlock(&codec->prepare_mutex);
+	return ret;
+}
+EXPORT_SYMBOL_HDA(snd_hda_codec_prepare);
+
+void snd_hda_codec_cleanup(struct hda_codec *codec,
+			   struct hda_pcm_stream *hinfo,
+			   struct snd_pcm_substream *substream)
+{
+	mutex_lock(&codec->prepare_mutex);
+	hinfo->ops.cleanup(hinfo, codec, substream);
+	mutex_unlock(&codec->prepare_mutex);
+}
+EXPORT_SYMBOL_HDA(snd_hda_codec_cleanup);
 
 /* global */
 const char *snd_hda_pcm_type_name[HDA_PCM_NTYPES] = {

sound/pci/hda/hda_codec.h

···
 
 	struct mutex spdif_mutex;
 	struct mutex control_mutex;
+	struct mutex prepare_mutex;
 	unsigned int spdif_status;	/* IEC958 status bits */
 	unsigned short spdif_ctls;	/* SPDIF control bits */
 	unsigned int spdif_in_enable;	/* SPDIF input enable? */
 	hda_nid_t *slave_dig_outs; /* optional digital out slave widgets */
 	struct snd_array init_pins;	/* initial (BIOS) pin configurations */
 	struct snd_array driver_pins;	/* pin configs set by codec parser */
+	struct snd_array cvt_setups;	/* audio convert setups */
 
 #ifdef CONFIG_SND_HDA_HWDEP
 	struct snd_hwdep *hwdep;	/* assigned hwdep device */
···
  */
 int snd_hda_build_pcms(struct hda_bus *bus);
 int snd_hda_codec_build_pcms(struct hda_codec *codec);
+
+int snd_hda_codec_prepare(struct hda_codec *codec,
+			  struct hda_pcm_stream *hinfo,
+			  unsigned int stream,
+			  unsigned int format,
+			  struct snd_pcm_substream *substream);
+void snd_hda_codec_cleanup(struct hda_codec *codec,
+			   struct hda_pcm_stream *hinfo,
+			   struct snd_pcm_substream *substream);
+
 void snd_hda_codec_setup_stream(struct hda_codec *codec, hda_nid_t nid,
 				u32 stream_tag,
 				int channel_id, int format);

sound/pci/hda/hda_intel.c

···
 	azx_dev->period_bytes = 0;
 	azx_dev->format_val = 0;
 
-	hinfo->ops.cleanup(hinfo, apcm->codec, substream);
+	snd_hda_codec_cleanup(apcm->codec, hinfo, substream);
 
 	return snd_pcm_lib_free_pages(substream);
 }
···
 	else
 		azx_dev->fifo_size = 0;
 
-	return hinfo->ops.prepare(hinfo, apcm->codec, azx_dev->stream_tag,
-				  azx_dev->format_val, substream);
+	return snd_hda_codec_prepare(apcm->codec, hinfo, azx_dev->stream_tag,
+				     azx_dev->format_val, substream);
 }
 
 static int azx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)