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Diffstat (limited to 'sound/firewire/amdtp.c')
-rw-r--r--sound/firewire/amdtp.c49
1 files changed, 48 insertions, 1 deletions
diff --git a/sound/firewire/amdtp.c b/sound/firewire/amdtp.c
index 87657dd7714c..ea995af6d049 100644
--- a/sound/firewire/amdtp.c
+++ b/sound/firewire/amdtp.c
@@ -31,6 +31,8 @@
#define INTERRUPT_INTERVAL 16
#define QUEUE_LENGTH 48
+static void pcm_period_tasklet(unsigned long data);
+
/**
* amdtp_out_stream_init - initialize an AMDTP output stream structure
* @s: the AMDTP output stream to initialize
@@ -47,6 +49,7 @@ int amdtp_out_stream_init(struct amdtp_out_stream *s, struct fw_unit *unit,
s->flags = flags;
s->context = ERR_PTR(-1);
mutex_init(&s->mutex);
+ tasklet_init(&s->period_tasklet, pcm_period_tasklet, (unsigned long)s);
s->packet_index = 0;
return 0;
@@ -164,6 +167,21 @@ void amdtp_out_stream_set_pcm_format(struct amdtp_out_stream *s,
}
EXPORT_SYMBOL(amdtp_out_stream_set_pcm_format);
+/**
+ * amdtp_out_stream_pcm_prepare - prepare PCM device for running
+ * @s: the AMDTP output stream
+ *
+ * This function should be called from the PCM device's .prepare callback.
+ */
+void amdtp_out_stream_pcm_prepare(struct amdtp_out_stream *s)
+{
+ tasklet_kill(&s->period_tasklet);
+ s->pcm_buffer_pointer = 0;
+ s->pcm_period_pointer = 0;
+ s->pointer_flush = true;
+}
+EXPORT_SYMBOL(amdtp_out_stream_pcm_prepare);
+
static unsigned int calculate_data_blocks(struct amdtp_out_stream *s)
{
unsigned int phase, data_blocks;
@@ -376,11 +394,21 @@ static void queue_out_packet(struct amdtp_out_stream *s, unsigned int cycle)
s->pcm_period_pointer += data_blocks;
if (s->pcm_period_pointer >= pcm->runtime->period_size) {
s->pcm_period_pointer -= pcm->runtime->period_size;
- snd_pcm_period_elapsed(pcm);
+ s->pointer_flush = false;
+ tasklet_hi_schedule(&s->period_tasklet);
}
}
}
+static void pcm_period_tasklet(unsigned long data)
+{
+ struct amdtp_out_stream *s = (void *)data;
+ struct snd_pcm_substream *pcm = ACCESS_ONCE(s->pcm);
+
+ if (pcm)
+ snd_pcm_period_elapsed(pcm);
+}
+
static void out_packet_callback(struct fw_iso_context *context, u32 cycle,
size_t header_length, void *header, void *data)
{
@@ -506,6 +534,24 @@ err_unlock:
EXPORT_SYMBOL(amdtp_out_stream_start);
/**
+ * amdtp_out_stream_pcm_pointer - get the PCM buffer position
+ * @s: the AMDTP output stream that transports the PCM data
+ *
+ * Returns the current buffer position, in frames.
+ */
+unsigned long amdtp_out_stream_pcm_pointer(struct amdtp_out_stream *s)
+{
+ /* this optimization is allowed to be racy */
+ if (s->pointer_flush)
+ fw_iso_context_flush_completions(s->context);
+ else
+ s->pointer_flush = true;
+
+ return ACCESS_ONCE(s->pcm_buffer_pointer);
+}
+EXPORT_SYMBOL(amdtp_out_stream_pcm_pointer);
+
+/**
* amdtp_out_stream_update - update the stream after a bus reset
* @s: the AMDTP output stream
*/
@@ -532,6 +578,7 @@ void amdtp_out_stream_stop(struct amdtp_out_stream *s)
return;
}
+ tasklet_kill(&s->period_tasklet);
fw_iso_context_stop(s->context);
fw_iso_context_destroy(s->context);
s->context = ERR_PTR(-1);