Split out virtio_snd_pcm_start_stop(). This is a preparation
for the next patch so that it doesn't become too big.

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>
---
 hw/audio/trace-events |  3 ++-
 hw/audio/virtio-snd.c | 57 ++++++++++++++++++++++++++++---------------
 2 files changed, 39 insertions(+), 21 deletions(-)

diff --git a/hw/audio/trace-events b/hw/audio/trace-events
index b1870ff224..7554bfcc60 100644
--- a/hw/audio/trace-events
+++ b/hw/audio/trace-events
@@ -50,7 +50,8 @@ virtio_snd_unrealize(void *snd) "snd %p: unrealize"
 virtio_snd_handle_pcm_set_params(uint32_t stream) "VIRTIO_SND_PCM_SET_PARAMS called for stream %"PRIu32
 virtio_snd_handle_ctrl(void *vdev, void *vq) "snd %p: handle ctrl event for queue %p"
 virtio_snd_handle_pcm_info(uint32_t stream) "VIRTIO_SND_R_PCM_INFO called for stream %"PRIu32
-virtio_snd_handle_pcm_start_stop(const char *code, uint32_t stream) "%s called for stream %"PRIu32
+virtio_snd_handle_pcm_start(uint32_t stream) "VIRTIO_SND_R_PCM_START called for stream %"PRIu32
+virtio_snd_handle_pcm_stop(uint32_t stream) "VIRTIO_SND_R_PCM_STOP called for stream %"PRIu32
 virtio_snd_handle_pcm_release(uint32_t stream) "VIRTIO_SND_PCM_RELEASE called for stream %"PRIu32
 virtio_snd_handle_code(uint32_t val, const char *code) "ctrl code msg val = %"PRIu32" == %s"
 virtio_snd_handle_chmap_info(void) "VIRTIO_SND_CHMAP_INFO called"
diff --git a/hw/audio/virtio-snd.c b/hw/audio/virtio-snd.c
index 2b630ada82..435ce26430 100644
--- a/hw/audio/virtio-snd.c
+++ b/hw/audio/virtio-snd.c
@@ -533,7 +533,42 @@ static void virtio_snd_handle_pcm_prepare(VirtIOSound *s,
 }
 
 /*
- * Handles VIRTIO_SND_R_PCM_START.
+ * Starts/Stops a VirtIOSound card stream.
+ * Returns the response status code. (VIRTIO_SND_S_*).
+ *
+ * @s: VirtIOSound device
+ * @stream_id: stream id
+ * @start: whether to start or stop the stream
+ */
+static uint32_t virtio_snd_pcm_start_stop(VirtIOSound *s,
+                                          uint32_t stream_id,
+                                          bool start)
+{
+    VirtIOSoundPCMStream *stream;
+
+    stream = virtio_snd_pcm_get_stream(s, stream_id);
+    if (!stream) {
+        return cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
+    }
+
+    if (start) {
+        trace_virtio_snd_handle_pcm_start(stream_id);
+    } else {
+        trace_virtio_snd_handle_pcm_stop(stream_id);
+    }
+
+    stream->active = start;
+    if (stream->info.direction == VIRTIO_SND_D_OUTPUT) {
+        AUD_set_active_out(stream->voice.out, start);
+    } else {
+        AUD_set_active_in(stream->voice.in, start);
+    }
+
+    return cpu_to_le32(VIRTIO_SND_S_OK);
+}
+
+/*
+ * Handles VIRTIO_SND_R_PCM_START and VIRTIO_SND_R_PCM_STOP.
  *
  * @s: VirtIOSound device
  * @cmd: The request command queue element from VirtIOSound cmdq field
@@ -543,7 +578,6 @@ static void virtio_snd_handle_pcm_start_stop(VirtIOSound *s,
                                              virtio_snd_ctrl_command *cmd,
                                              bool start)
 {
-    VirtIOSoundPCMStream *stream;
     virtio_snd_pcm_hdr req;
     uint32_t stream_id;
     size_t msg_sz = iov_to_buf(cmd->elem->out_sg,
@@ -561,24 +595,7 @@ static void virtio_snd_handle_pcm_start_stop(VirtIOSound *s,
     }
 
     stream_id = le32_to_cpu(req.stream_id);
-    cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_OK);
-    trace_virtio_snd_handle_pcm_start_stop(start ? "VIRTIO_SND_R_PCM_START" :
-            "VIRTIO_SND_R_PCM_STOP", stream_id);
-
-    stream = virtio_snd_pcm_get_stream(s, stream_id);
-    if (stream) {
-        stream->active = start;
-        if (stream->info.direction == VIRTIO_SND_D_OUTPUT) {
-            AUD_set_active_out(stream->voice.out, start);
-        } else {
-            AUD_set_active_in(stream->voice.in, start);
-        }
-    } else {
-        error_report("Invalid stream id: %"PRIu32, stream_id);
-        cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
-        return;
-    }
-    stream->active = start;
+    cmd->resp.code = virtio_snd_pcm_start_stop(s, stream_id, start);
 }
 
 /*
-- 
2.35.3