ALSA: dice: use cache of stream format to check running stream

At present, to check running stream, available stream formats are used
at current sampling transmission frequency (stf). But when changing stf,
it's convenient to use cache of stream formats.

This commit applies this idea.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/dice/dice-stream.c

@@ -294,16 +294,14 @@ int snd_dice_stream_start_duplex(struct snd_dice *dice, unsigned int rate)
 	unsigned int curr_rate;
 	unsigned int i;
 	struct reg_params tx_params, rx_params;
-	bool need_to_start;
+	bool need_to_start = false;
+	enum snd_dice_rate_mode mode;
 	int err;
 
 	if (dice->substreams_counter == 0)
 		return -EIO;
 
-	err = get_register_params(dice, &tx_params, &rx_params);
-	if (err < 0)
-		return err;
-
+	/* Check sampling transmission frequency. */
 	err = snd_dice_transaction_get_rate(dice, &curr_rate);
 	if (err < 0) {
 		dev_err(&dice->unit->device,
@@ -315,22 +313,36 @@ int snd_dice_stream_start_duplex(struct snd_dice *dice, unsigned int rate)
 	if (rate != curr_rate)
 		return -EINVAL;
 
-	/* Judge to need to restart streams. */
-	for (i = 0; i < MAX_STREAMS; i++) {
-		if (i < tx_params.count) {
-			if (amdtp_streaming_error(&dice->tx_stream[i]) ||
-			    !amdtp_stream_running(&dice->tx_stream[i]))
+	/* Check error of packet streaming. */
+	for (i = 0; i < MAX_STREAMS; ++i) {
+		if (amdtp_streaming_error(&dice->tx_stream[i]))
+			break;
+		if (amdtp_streaming_error(&dice->rx_stream[i]))
 			break;
 	}
-		if (i < rx_params.count) {
-			if (amdtp_streaming_error(&dice->rx_stream[i]) ||
+	if (i < MAX_STREAMS)
+		need_to_start = true;
+
+	/* Check required streams are running or not. */
+	err = snd_dice_stream_get_rate_mode(dice, rate, &mode);
+	if (err < 0)
+		return err;
+	for (i = 0; i < MAX_STREAMS; ++i) {
+		if (dice->tx_pcm_chs[i][mode] > 0 &&
+		    !amdtp_stream_running(&dice->tx_stream[i]))
+			break;
+		if (dice->rx_pcm_chs[i][mode] > 0 &&
 		    !amdtp_stream_running(&dice->rx_stream[i]))
 			break;
 	}
-	}
-	need_to_start = (i < MAX_STREAMS);
+	if (i < MAX_STREAMS)
+		need_to_start = true;
 
 	if (need_to_start) {
+		err = get_register_params(dice, &tx_params, &rx_params);
+		if (err < 0)
+			return err;
+
 		/* Stop transmission. */
 		snd_dice_transaction_clear_enable(dice);
 		stop_streams(dice, AMDTP_IN_STREAM, &tx_params);
@@ -341,7 +353,7 @@ int snd_dice_stream_start_duplex(struct snd_dice *dice, unsigned int rate)
 		if (err < 0) {
 			dev_err(&dice->unit->device,
 				"fail to ensure phase lock\n");
-			return err;
+			goto error;
 		}
 
 		/* Start both streams. */