ALSA: dice: share PCM buffer size for both direction

This commit allows ALSA dice driver to share PCM buffer size for both
capture and playback PCM substream. When AMDTP domain starts for one
of the PCM substream, buffer size of the PCM substream is stores to
AMDTP domain structure. Some AMDTP streams have already run with the
buffer size when another PCM substream starts, therefore the PCM
substream has a constraint to its buffer size.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20191017155424.885-6-o-takashi@sakamocchi.jpSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/dice/dice-midi.c

@@ -17,7 +17,7 @@ static int midi_open(struct snd_rawmidi_substream *substream)
 
 	mutex_lock(&dice->mutex);
 
-	err = snd_dice_stream_reserve_duplex(dice, 0, 0);
+	err = snd_dice_stream_reserve_duplex(dice, 0, 0, 0);
 	if (err >= 0) {
 		++dice->substreams_counter;
 		err = snd_dice_stream_start_duplex(dice);

sound/firewire/dice/dice-pcm.c

@@ -204,6 +204,7 @@ static int pcm_open(struct snd_pcm_substream *substream)
 	if (!internal ||
 	    (dice->substreams_counter > 0 && d->events_per_period > 0)) {
 		unsigned int frames_per_period = d->events_per_period;
+		unsigned int frames_per_buffer = d->events_per_buffer;
 		unsigned int rate;
 
 		err = snd_dice_transaction_get_rate(dice, &rate);
@@ -217,8 +218,10 @@ static int pcm_open(struct snd_pcm_substream *substream)
 
 		if (frames_per_period > 0) {
 			// For double_pcm_frame quirk.
-			if (rate > 96000)
+			if (rate > 96000) {
 				frames_per_period *= 2;
+				frames_per_buffer *= 2;
+			}
 
 			err = snd_pcm_hw_constraint_minmax(substream->runtime,
 					SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
@@ -227,6 +230,14 @@ static int pcm_open(struct snd_pcm_substream *substream)
 				mutex_unlock(&dice->mutex);
 				goto err_locked;
 			}
+
+			err = snd_pcm_hw_constraint_minmax(substream->runtime,
+					SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
+					frames_per_buffer, frames_per_buffer);
+			if (err < 0) {
+				mutex_unlock(&dice->mutex);
+				goto err_locked;
+			}
 		}
 	}
 
@@ -263,13 +274,16 @@ static int pcm_hw_params(struct snd_pcm_substream *substream,
 	if (substream->runtime->status->state == SNDRV_PCM_STATE_OPEN) {
 		unsigned int rate = params_rate(hw_params);
 		unsigned int events_per_period = params_period_size(hw_params);
+		unsigned int events_per_buffer = params_buffer_size(hw_params);
 
 		mutex_lock(&dice->mutex);
 		// For double_pcm_frame quirk.
-		if (rate > 96000)
+		if (rate > 96000) {
 			events_per_period /= 2;
+			events_per_buffer /= 2;
+		}
 		err = snd_dice_stream_reserve_duplex(dice, rate,
-						     events_per_period);
+					events_per_period, events_per_buffer);
 		if (err >= 0)
 			++dice->substreams_counter;
 		mutex_unlock(&dice->mutex);

sound/firewire/dice/dice-stream.c

@@ -279,7 +279,8 @@ static void finish_session(struct snd_dice *dice, struct reg_params *tx_params,
 }
 
 int snd_dice_stream_reserve_duplex(struct snd_dice *dice, unsigned int rate,
-				   unsigned int events_per_period)
+				   unsigned int events_per_period,
+				   unsigned int events_per_buffer)
 {
 	unsigned int curr_rate;
 	int err;
@@ -327,7 +328,7 @@ int snd_dice_stream_reserve_duplex(struct snd_dice *dice, unsigned int rate,
 			goto error;
 
 		err = amdtp_domain_set_events_per_period(&dice->domain,
-							 events_per_period, 0);
+					events_per_period, events_per_buffer);
 		if (err < 0)
 			goto error;
 	}

sound/firewire/dice/dice.h

@@ -211,7 +211,8 @@ void snd_dice_stream_stop_duplex(struct snd_dice *dice);
 int snd_dice_stream_init_duplex(struct snd_dice *dice);
 void snd_dice_stream_destroy_duplex(struct snd_dice *dice);
 int snd_dice_stream_reserve_duplex(struct snd_dice *dice, unsigned int rate,
-				   unsigned int events_per_period);
+				   unsigned int events_per_period,
+				   unsigned int events_per_buffer);
 void snd_dice_stream_update_duplex(struct snd_dice *dice);
 int snd_dice_stream_detect_current_formats(struct snd_dice *dice);