audio: add offload underflow msg state

Signed-off-by: hanqiyuan <[email protected]>

audio/audio.c

@@ -834,6 +834,43 @@ static inline void audio_ioerr(FAR struct audio_upperhalf_s *upper,
     }
 }
 
+/****************************************************************************
+ * Name: audio_underrun
+ *
+ * Description:
+ *   Send an AUDIO_MSG_UNDERRUN message to the client to indicate that the
+ *   active playback is underrun.  The lower-half driver initiates this
+ *   call via its callback pointer to our upper-half driver.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_AUDIO_MULTI_SESSION
+static inline void audio_underrun(FAR struct audio_upperhalf_s *upper,
+                    FAR struct ap_buffer_s *apb, uint16_t status,
+                    FAR void *session)
+#else
+static inline void audio_underrun(FAR struct audio_upperhalf_s *upper,
+                    FAR struct ap_buffer_s *apb, uint16_t status)
+#endif
+{
+  struct audio_msg_s    msg;
+
+  audinfo("Entry\n");
+
+  /* Send a dequeue message to the user if a message queue is registered */
+
+  if (upper->usermq != NULL)
+    {
+      msg.msg_id = AUDIO_MSG_UNDERRUN;
+      msg.u.ptr = NULL;
+#ifdef CONFIG_AUDIO_MULTI_SESSION
+      msg.session = session;
+#endif
+      file_mq_send(upper->usermq, (FAR const char *)&msg, sizeof(msg),
+                   CONFIG_AUDIO_BUFFER_DEQUEUE_PRIO);
+    }
+}
+
 /****************************************************************************
  * Name: audio_callback
  *
@@ -923,6 +960,17 @@ static void audio_callback(FAR void *handle, uint16_t reason,
         }
         break;
 
+      case AUDIO_CALLBACK_UNDERRUN:
+        {
+          /* send underrun status */
+#ifdef CONFIG_AUDIO_MULTI_SESSION
+          audio_underrun(upper, apb, status, session);
+#else
+          audio_underrun(upper, apb, status);
+#endif
+        }
+        break;
+
       default:
         {
           auderr("ERROR: Unknown callback reason code %d\n", reason);

include/nuttx/audio/audio.h

@@ -328,6 +328,7 @@
 #define AUDIO_CALLBACK_IOERR        0x02
 #define AUDIO_CALLBACK_COMPLETE     0x03
 #define AUDIO_CALLBACK_MESSAGE      0x04
+#define AUDIO_CALLBACK_UNDERRUN     0x05
 
 /* Audio Pipeline Buffer (AP Buffer) flags **********************************/