ALSA: virtio: handling control and I/O messages for the PCM device

[linux-2.6-microblaze.git] / sound / virtio / virtio_pcm.c

diff --git a/sound/virtio/virtio_pcm.c b/sound/virtio/virtio_pcm.c
index e16567e..2dcd763 100644 (file)
--- a/sound/virtio/virtio_pcm.c
+++ b/sound/virtio/virtio_pcm.c
@@ -353,6 +353,8 @@ int virtsnd_pcm_parse_cfg(struct virtio_snd *snd)
                vss->snd = snd;
                vss->sid = i;
                INIT_WORK(&vss->elapsed_period, virtsnd_pcm_period_elapsed);
+               init_waitqueue_head(&vss->msg_empty);
+               spin_lock_init(&vss->lock);
 
                rc = virtsnd_pcm_build_hw(vss, &info[i]);
                if (rc)
@@ -477,3 +479,33 @@ int virtsnd_pcm_build_devs(struct virtio_snd *snd)
 
        return 0;
 }
+
+/**
+ * virtsnd_pcm_event() - Handle the PCM device event notification.
+ * @snd: VirtIO sound device.
+ * @event: VirtIO sound event.
+ *
+ * Context: Interrupt context.
+ */
+void virtsnd_pcm_event(struct virtio_snd *snd, struct virtio_snd_event *event)
+{
+       struct virtio_pcm_substream *vss;
+       u32 sid = le32_to_cpu(event->data);
+
+       if (sid >= snd->nsubstreams)
+               return;
+
+       vss = &snd->substreams[sid];
+
+       switch (le32_to_cpu(event->hdr.code)) {
+       case VIRTIO_SND_EVT_PCM_PERIOD_ELAPSED:
+               /* TODO: deal with shmem elapsed period */
+               break;
+       case VIRTIO_SND_EVT_PCM_XRUN:
+               spin_lock(&vss->lock);
+               if (vss->xfer_enabled)
+                       vss->xfer_xrun = true;
+               spin_unlock(&vss->lock);
+               break;
+       }
+}