ALSA: dice, firewire-lib: add blocking mode

Allow AMDTP output streams to use blocking mode.

Use it for DICE devices, because the old DICE-II chip will in some cases
not be able to lock to non-blocking streams (erratum E7).

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>

1 files changed, 29 insertions, 25 deletions

diff --git a/sound/firewire/amdtp.c b/sound/firewire/amdtp.c
index ea995af6d049..efb2e2947ce7 100644
--- a/sound/firewire/amdtp.c
+++ b/sound/firewire/amdtp.c
@@ -42,9 +42,6 @@ static void pcm_period_tasklet(unsigned long data);
 int amdtp_out_stream_init(struct amdtp_out_stream *s, struct fw_unit *unit,
                           enum cip_out_flags flags)
 {
-        if (flags != CIP_NONBLOCKING)
-                return -EINVAL;
-
         s->unit = fw_unit_get(unit);
         s->flags = flags;
         s->context = ERR_PTR(-1);
@@ -96,12 +93,20 @@ void amdtp_out_stream_set_rate(struct amdtp_out_stream *s, unsigned int rate)
                 return;
 
         for (sfc = 0; sfc < ARRAY_SIZE(rate_info); ++sfc)
-                if (rate_info[sfc].rate == rate) {
-                        s->sfc = sfc;
-                        s->syt_interval = rate_info[sfc].syt_interval;
-                        return;
-                }
+                if (rate_info[sfc].rate == rate)
+                        goto sfc_found;
         WARN_ON(1);
+        return;
+
+sfc_found:
+        s->sfc = sfc;
+        s->syt_interval = rate_info[sfc].syt_interval;
+
+        /* default buffering in the device */
+        s->transfer_delay = TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE;
+        if (s->flags & CIP_BLOCKING)
+                /* additional buffering needed to adjust for no-data packets */
+                s->transfer_delay += TICKS_PER_SECOND * s->syt_interval / rate;
 }
 EXPORT_SYMBOL(amdtp_out_stream_set_rate);
 
@@ -110,25 +115,15 @@ EXPORT_SYMBOL(amdtp_out_stream_set_rate);
  * @s: the AMDTP output stream
  *
  * This function must not be called before the stream has been configured
- * with amdtp_out_stream_set_hw_params(), amdtp_out_stream_set_pcm(), and
+ * with amdtp_out_stream_set_rate(), amdtp_out_stream_set_pcm(), and
  * amdtp_out_stream_set_midi().
  */
 unsigned int amdtp_out_stream_get_max_payload(struct amdtp_out_stream *s)
 {
-        static const unsigned int max_data_blocks[] = {
-                [CIP_SFC_32000]  =  4,
-                [CIP_SFC_44100]  =  6,
-                [CIP_SFC_48000]  =  6,
-                [CIP_SFC_88200]  = 12,
-                [CIP_SFC_96000]  = 12,
-                [CIP_SFC_176400] = 23,
-                [CIP_SFC_192000] = 24,
-        };
-
         s->data_block_quadlets = s->pcm_channels;
         s->data_block_quadlets += DIV_ROUND_UP(s->midi_ports, 8);
 
-        return 8 + max_data_blocks[s->sfc] * 4 * s->data_block_quadlets;
+        return 8 + s->syt_interval * s->data_block_quadlets * 4;
 }
 EXPORT_SYMBOL(amdtp_out_stream_get_max_payload);
 
@@ -248,7 +243,7 @@ static unsigned int calculate_syt(struct amdtp_out_stream *s,
         s->last_syt_offset = syt_offset;
 
         if (syt_offset < TICKS_PER_CYCLE) {
-                syt_offset += TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE;
+                syt_offset += s->transfer_delay;
                 syt = (cycle + syt_offset / TICKS_PER_CYCLE) << 12;
                 syt += syt_offset % TICKS_PER_CYCLE;
 
@@ -344,8 +339,17 @@ static void queue_out_packet(struct amdtp_out_stream *s, unsigned int cycle)
                 return;
         index = s->packet_index;
 
-        data_blocks = calculate_data_blocks(s);
         syt = calculate_syt(s, cycle);
+        if (!(s->flags & CIP_BLOCKING)) {
+                data_blocks = calculate_data_blocks(s);
+        } else {
+                if (syt != 0xffff) {
+                        data_blocks = s->syt_interval;
+                } else {
+                        data_blocks = 0;
+                        syt = 0xffffff;
+                }
+        }
 
         buffer = s->buffer.packets[index].buffer;
         buffer[0] = cpu_to_be32(ACCESS_ONCE(s->source_node_id_field) |
@@ -455,9 +459,9 @@ static int queue_initial_skip_packets(struct amdtp_out_stream *s)
  * @speed: firewire speed code
  *
  * The stream cannot be started until it has been configured with
- * amdtp_out_stream_set_hw_params(), amdtp_out_stream_set_pcm(), and
- * amdtp_out_stream_set_midi(); and it must be started before any
- * PCM or MIDI device can be started.
+ * amdtp_out_stream_set_rate(), amdtp_out_stream_set_pcm(),
+ * amdtp_out_stream_set_midi(), and amdtp_out_stream_set_format();
+ * and it must be started before any PCM or MIDI device can be started.
  */
 int amdtp_out_stream_start(struct amdtp_out_stream *s, int channel, int speed)
 {