ALSA: firewire-lib, firewire-speakers: handle packet queueing errors

Add an AMDTP stream error state that occurs when we fail to queue
another packet.  In this case, the stream is stopped, and the error can
be reported when the application tries to restart the PCM stream.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 13 insertions, 1 deletions

diff --git a/sound/firewire/amdtp.h b/sound/firewire/amdtp.h
index 02dc1a664b55..537a9cb83581 100644
--- a/sound/firewire/amdtp.h
+++ b/sound/firewire/amdtp.h
@@ -56,7 +56,7 @@ struct amdtp_out_stream {
 
         struct snd_pcm_substream *pcm;
 
-        unsigned int packet_counter;
+        int packet_index;
         unsigned int data_block_counter;
 
         unsigned int data_block_state;
@@ -111,6 +111,18 @@ static inline void amdtp_out_stream_set_midi(struct amdtp_out_stream *s,
 }
 
 /**
+ * amdtp_out_streaming_error - check for streaming error
+ * @s: the AMDTP output stream
+ *
+ * If this function returns true, the stream's packet queue has stopped due to
+ * an asynchronous error.
+ */
+static inline bool amdtp_out_streaming_error(struct amdtp_out_stream *s)
+{
+        return s->packet_index < 0;
+}
+
+/**
  * amdtp_out_stream_pcm_prepare - prepare PCM device for running
  * @s: the AMDTP output stream
  *