ALSA: oxfw: perform sequence replay for media clock recovery

[sfrench/cifs-2.6.git] / sound / firewire / oxfw / oxfw-stream.c

diff --git a/sound/firewire/oxfw/oxfw-stream.c b/sound/firewire/oxfw/oxfw-stream.c
index 9792d4b4373ced23b785b23ab8f8cef3a67323fc..0ef242fdd3bc38dd7341fe81246814020f6cbf9b 100644 (file)
--- a/sound/firewire/oxfw/oxfw-stream.c
+++ b/sound/firewire/oxfw/oxfw-stream.c
@@ -153,13 +153,13 @@ static int init_stream(struct snd_oxfw *oxfw, struct amdtp_stream *stream)
        struct cmp_connection *conn;
        enum cmp_direction c_dir;
        enum amdtp_stream_direction s_dir;
-       unsigned int flags;
+       unsigned int flags = CIP_UNAWARE_SYT;
        int err;
 
        if (!(oxfw->quirks & SND_OXFW_QUIRK_BLOCKING_TRANSMISSION))
-               flags = CIP_NONBLOCKING;
+               flags |= CIP_NONBLOCKING;
        else
-               flags = CIP_BLOCKING;
+               flags |= CIP_BLOCKING;
 
        if (stream == &oxfw->tx_stream) {
                conn = &oxfw->out_conn;
@@ -337,6 +337,9 @@ int snd_oxfw_stream_start_duplex(struct snd_oxfw *oxfw)
        }
 
        if (!amdtp_stream_running(&oxfw->rx_stream)) {
+               unsigned int tx_init_skip_cycles = 0;
+               bool replay_seq = false;
+
                err = start_stream(oxfw, &oxfw->rx_stream);
                if (err < 0) {
                        dev_err(&oxfw->unit->device,
@@ -352,9 +355,20 @@ int snd_oxfw_stream_start_duplex(struct snd_oxfw *oxfw)
                                        "fail to prepare tx stream: %d\n", err);
                                goto error;
                        }
+
+                       if (oxfw->quirks & SND_OXFW_QUIRK_JUMBO_PAYLOAD) {
+                               // Just after changing sampling transfer frequency, many cycles are
+                               // skipped for packet transmission.
+                               tx_init_skip_cycles = 400;
+                       } else {
+                               replay_seq = true;
+                       }
                }
 
-               err = amdtp_domain_start(&oxfw->domain, 0, false, false);
+               // NOTE: The device ignores presentation time expressed by the value of syt field
+               // of CIP header in received packets. The sequence of the number of data blocks per
+               // packet is important for media clock recovery.
+               err = amdtp_domain_start(&oxfw->domain, tx_init_skip_cycles, replay_seq, false);
                if (err < 0)
                        goto error;