Let sound playing continuously in pcm_start state

Author: Cuda-Chen

virtio-snd.c

@@ -8,9 +8,9 @@
 #include "CNFA_sf.h"
 
 #include "device.h"
-#include "utils.h"
 #include "riscv.h"
 #include "riscv_private.h"
+#include "utils.h"
 #include "virtio.h"
 
 #define VSND_DEV_CNT_MAX 1
@@ -622,29 +622,23 @@ static void virtio_snd_cb(struct CNFADriver *dev,
 {
     (void) in; /* reversed for future recording use */
     vsnd_stream_sel_t *v_ptr = (vsnd_stream_sel_t *) dev->opaque;
+    int channels = dev->channelsPlay;
+    uint32_t out_buf_sz = framesp * channels;
 
     pthread_mutex_lock(&virtio_snd_ctrl_mutex);
 
-    while (v_ptr->guest_playing <= 0) {
+    while (v_ptr->guest_playing == 0) {
         fprintf(stderr, "wait ctrl cond\n");
+        memset(out, 0, sizeof(*out) * out_buf_sz);
         pthread_cond_wait(&virtio_snd_ctrl_cond, &virtio_snd_ctrl_mutex);
     }
 
-    v_ptr->guest_playing--;
-
     totalframesr += framesr;
     totalframesp += framesp;
 
-    int channels = dev->channelsPlay;
     uint32_t id = v_ptr->stream_id;
-    uint32_t out_buf_sz = framesp * channels;
     fprintf(stderr, "start to play with out_buf_sz %" PRIu32 "\n", out_buf_sz);
 
-    /*if (!(playing)) {
-        memset(out, 0, sizeof(short) * out_buf_sz);
-        return;
-    }*/
-
     /* TODO: add single consumer */
     __virtio_snd_frame_dequeue(out, out_buf_sz, id);
 #if 0