ALSA: firewire-digi00x: share PCM buffer size for both direction

This commit allows ALSA firewire-digi00x 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/20191017155424.885-7-o-takashi@sakamocchi.jpSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/digi00x/digi00x-midi.c

@@ -17,7 +17,7 @@ static int midi_open(struct snd_rawmidi_substream *substream)
 		return err;
 
 	mutex_lock(&dg00x->mutex);
-	err = snd_dg00x_stream_reserve_duplex(dg00x, 0, 0);
+	err = snd_dg00x_stream_reserve_duplex(dg00x, 0, 0, 0);
 	if (err >= 0) {
 		++dg00x->substreams_counter;
 		err = snd_dg00x_stream_start_duplex(dg00x);

sound/firewire/digi00x/digi00x-pcm.c

@@ -135,6 +135,7 @@ static int pcm_open(struct snd_pcm_substream *substream)
 	if ((clock != SND_DG00X_CLOCK_INTERNAL) ||
 	    (dg00x->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_dg00x_stream_get_external_rate(dg00x, &rate);
@@ -153,6 +154,14 @@ static int pcm_open(struct snd_pcm_substream *substream)
 				mutex_unlock(&dg00x->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(&dg00x->mutex);
+				goto err_locked;
+			}
 		}
 	}
 
@@ -189,10 +198,11 @@ 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 frames_per_period = params_period_size(hw_params);
+		unsigned int frames_per_buffer = params_buffer_size(hw_params);
 
 		mutex_lock(&dg00x->mutex);
 		err = snd_dg00x_stream_reserve_duplex(dg00x, rate,
-						      frames_per_period);
+					frames_per_period, frames_per_buffer);
 		if (err >= 0)
 			++dg00x->substreams_counter;
 		mutex_unlock(&dg00x->mutex);

sound/firewire/digi00x/digi00x-stream.c

@@ -284,7 +284,8 @@ void snd_dg00x_stream_destroy_duplex(struct snd_dg00x *dg00x)
 }
 
 int snd_dg00x_stream_reserve_duplex(struct snd_dg00x *dg00x, unsigned int rate,
-				    unsigned int frames_per_period)
+				    unsigned int frames_per_period,
+				    unsigned int frames_per_buffer)
 {
 	unsigned int curr_rate;
 	int err;
@@ -318,7 +319,7 @@ int snd_dg00x_stream_reserve_duplex(struct snd_dg00x *dg00x, unsigned int rate,
 		}
 
 		err = amdtp_domain_set_events_per_period(&dg00x->domain,
-							 frames_per_period, 0);
+					frames_per_period, frames_per_buffer);
 		if (err < 0) {
 			fw_iso_resources_free(&dg00x->rx_resources);
 			fw_iso_resources_free(&dg00x->tx_resources);

sound/firewire/digi00x/digi00x.h

@@ -142,7 +142,8 @@ int snd_dg00x_stream_check_external_clock(struct snd_dg00x *dg00x,
 					  bool *detect);
 int snd_dg00x_stream_init_duplex(struct snd_dg00x *dg00x);
 int snd_dg00x_stream_reserve_duplex(struct snd_dg00x *dg00x, unsigned int rate,
-				    unsigned int frames_per_period);
+				    unsigned int frames_per_period,
+				    unsigned int frames_per_buffer);
 int snd_dg00x_stream_start_duplex(struct snd_dg00x *dg00x);
 void snd_dg00x_stream_stop_duplex(struct snd_dg00x *dg00x);
 void snd_dg00x_stream_update_duplex(struct snd_dg00x *dg00x);