Set TX response used length

Author: Cuda-Chen

virtio-snd.c

@@ -748,6 +748,7 @@ static int virtio_snd_tx_desc_handler(virtio_snd_state_t *vsnd,
     struct queue_head frame_q = vsnd_props[stream_id].pcm_frames_q;
     INIT_QUEUE_HEAD(&frame_q);
     virtio_snd_pcm_frame_t *frame = vsnd_props[stream_id].pcm_frames;
+    uint32_t ret_len = 0;
     queue_for_each_entry(node, &q, q)
     {
         uint32_t addr = node->vq_desc.addr;
@@ -765,8 +766,8 @@ static int virtio_snd_tx_desc_handler(virtio_snd_state_t *vsnd,
                 (virtio_snd_pcm_status_t *) (base + addr);
             response->status = VIRTIO_SND_S_OK;
             response->latency_bytes =
-                0;                     /* TODO: show the actual latency bytes */
-            *plen = sizeof(*response); /* TODO: set the read length of buffer of
+                0;           /* TODO: show the actual latency bytes */
+            *plen = ret_len; /* TODO: set the read length of buffer of
                                           PCM frames */
             fprintf(stderr, "TX response\n");
             goto early_continue;
@@ -777,6 +778,7 @@ static int virtio_snd_tx_desc_handler(virtio_snd_state_t *vsnd,
         frame->buf = (void *) malloc(sizeof(frame->buf) * len);
         memcpy(frame->buf, buf, len);
         queue_push(&frame->q, &frame_q);
+        ret_len += len;
 
     early_continue:
         idx++;
@@ -857,6 +859,7 @@ static void virtio_queue_notify_handler(
          */
         uint32_t len = 0;
         int result = handler(vsnd, queue, buffer_idx, &len);
+        fprintf(stderr, "len: %" PRIu32 "\n", len);
         if (result != 0)
             return virtio_snd_set_fail(vsnd);