1 files changed, 27 insertions, 6 deletions

diff --git a/sound/firewire/dice.c b/sound/firewire/dice.c
index 26b2158f87d1..cd4c6b6d072e 100644
--- a/sound/firewire/dice.c
+++ b/sound/firewire/dice.c
@@ -563,7 +563,7 @@ static int dice_hw_params(struct snd_pcm_substream *substream,
                           struct snd_pcm_hw_params *hw_params)
 {
         struct dice *dice = substream->private_data;
-        unsigned int rate_index, mode;
+        unsigned int rate_index, mode, rate, channels, i;
         int err;
 
         mutex_lock(&dice->mutex);
@@ -575,15 +575,36 @@ static int dice_hw_params(struct snd_pcm_substream *substream,
         if (err < 0)
                 return err;
 
-        rate_index = rate_to_index(params_rate(hw_params));
+        rate = params_rate(hw_params);
+        rate_index = rate_to_index(rate);
         err = dice_change_rate(dice, rate_index << CLOCK_RATE_SHIFT);
         if (err < 0)
                 return err;
 
+        /*
+         * At rates above 96 kHz, pretend that the stream runs at half the
+         * actual sample rate with twice the number of channels; two samples
+         * of a channel are stored consecutively in the packet. Requires
+         * blocking mode and PCM buffer size should be aligned to SYT_INTERVAL.
+         */
+        channels = params_channels(hw_params);
+        if (rate_index > 4) {
+                if (channels > AMDTP_MAX_CHANNELS_FOR_PCM / 2) {
+                        err = -ENOSYS;
+                        return err;
+                }
+
+                for (i = 0; i < channels; i++) {
+                        dice->stream.pcm_positions[i * 2] = i;
+                        dice->stream.pcm_positions[i * 2 + 1] = i + channels;
+                }
+
+                rate /= 2;
+                channels *= 2;
+        }
+
         mode = rate_index_to_mode(rate_index);
-        amdtp_stream_set_parameters(&dice->stream,
-                                    params_rate(hw_params),
-                                    params_channels(hw_params),
+        amdtp_stream_set_parameters(&dice->stream, rate, channels,
                                     dice->rx_midi_ports[mode]);
         amdtp_stream_set_pcm_format(&dice->stream,
                                     params_format(hw_params));
@@ -1361,7 +1382,7 @@ static int dice_probe(struct fw_unit *unit, const struct ieee1394_device_id *id)
         dice->resources.channels_mask = 0x00000000ffffffffuLL;
 
         err = amdtp_stream_init(&dice->stream, unit, AMDTP_OUT_STREAM,
-                                CIP_BLOCKING | CIP_HI_DUALWIRE);
+                                CIP_BLOCKING);
         if (err < 0)
                 goto err_resources;