ALSA: fireworks: use the same size of period for PCM substream in AMDTP streams

[linux-2.6-block.git] / sound / firewire / fireworks / fireworks_pcm.c

diff --git a/sound/firewire/fireworks/fireworks_pcm.c b/sound/firewire/fireworks/fireworks_pcm.c
index 35fc95283423f671d4500ced1c32ec596687e32b..314d1f8b834480362af02ebb60ff0d75789e78e7 100644 (file)
--- a/sound/firewire/fireworks/fireworks_pcm.c
+++ b/sound/firewire/fireworks/fireworks_pcm.c
@@ -173,13 +173,13 @@ end:
 static int pcm_open(struct snd_pcm_substream *substream)
 {
        struct snd_efw *efw = substream->private_data;
-       unsigned int sampling_rate;
+       struct amdtp_domain *d = &efw->domain;
        enum snd_efw_clock_source clock_source;
        int err;
 
        err = snd_efw_stream_lock_try(efw);
        if (err < 0)
-               goto end;
+               return err;
 
        err = pcm_init_hw_params(efw, substream);
        if (err < 0)
@@ -189,23 +189,40 @@ static int pcm_open(struct snd_pcm_substream *substream)
        if (err < 0)
                goto err_locked;
 
-       /*
-        * When source of clock is not internal or any PCM streams are running,
-        * available sampling rate is limited at current sampling rate.
-        */
+       mutex_lock(&efw->mutex);
+
+       // When source of clock is not internal or any stream is reserved for
+       // transmission of PCM frames, the available sampling rate is limited
+       // at current one.
        if ((clock_source != SND_EFW_CLOCK_SOURCE_INTERNAL) ||
-           amdtp_stream_pcm_running(&efw->tx_stream) ||
-           amdtp_stream_pcm_running(&efw->rx_stream)) {
+           (efw->substreams_counter > 0 && d->events_per_period > 0)) {
+               unsigned int frames_per_period = d->events_per_period;
+               unsigned int sampling_rate;
+
                err = snd_efw_command_get_sampling_rate(efw, &sampling_rate);
-               if (err < 0)
+               if (err < 0) {
+                       mutex_unlock(&efw->mutex);
                        goto err_locked;
+               }
                substream->runtime->hw.rate_min = sampling_rate;
                substream->runtime->hw.rate_max = sampling_rate;
+
+               if (frames_per_period > 0) {
+                       err = snd_pcm_hw_constraint_minmax(substream->runtime,
+                                       SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
+                                       frames_per_period, frames_per_period);
+                       if (err < 0) {
+                               mutex_unlock(&efw->mutex);
+                               goto err_locked;
+                       }
+               }
        }
 
+       mutex_unlock(&efw->mutex);
+
        snd_pcm_set_sync(substream);
-end:
-       return err;
+
+       return 0;
 err_locked:
        snd_efw_stream_lock_release(efw);
        return err;