On Sat, 27 Feb 2021 09:59:56 +0100,
Anton Yakovlev wrote:
All running PCM substreams are stopped on device suspend and restarted
on device resume.
Signed-off-by: Anton Yakovlev <anton.yakovlev@xxxxxxxxxxxxxxx>
---
sound/virtio/virtio_card.c | 56 +++++++++++++++++++++++++++++++++++
sound/virtio/virtio_pcm.c | 1 +
sound/virtio/virtio_pcm_ops.c | 41 ++++++++++++++++++++-----
3 files changed, 90 insertions(+), 8 deletions(-)
diff --git a/sound/virtio/virtio_card.c b/sound/virtio/virtio_card.c
index 59455a562018..c7ae8801991d 100644
--- a/sound/virtio/virtio_card.c
+++ b/sound/virtio/virtio_card.c
@@ -323,6 +323,58 @@ static void virtsnd_remove(struct virtio_device *vdev)
kfree(snd->event_msgs);
}
+#ifdef CONFIG_PM_SLEEP
+/**
+ * virtsnd_freeze() - Suspend device.
+ * @vdev: VirtIO parent device.
+ *
+ * Context: Any context.
+ * Return: 0 on success, -errno on failure.
+ */
+static int virtsnd_freeze(struct virtio_device *vdev)
+{
+ struct virtio_snd *snd = vdev->priv;
+
+ virtsnd_ctl_msg_cancel_all(snd);
+
+ vdev->config->del_vqs(vdev);
+ vdev->config->reset(vdev);
+
+ kfree(snd->event_msgs);
+
+ /*
+ * If the virtsnd_restore() fails before re-allocating events, then we
+ * get a dangling pointer here.
+ */
+ snd->event_msgs = NULL;
+
+ return 0;
I suppose some cancel of inflight works is needed?
Ditto for the device removal, too.
--- a/sound/virtio/virtio_pcm.c
+++ b/sound/virtio/virtio_pcm.c
@@ -109,6 +109,7 @@ static int virtsnd_pcm_build_hw(struct virtio_pcm_substream *vss,
SNDRV_PCM_INFO_BATCH |
SNDRV_PCM_INFO_BLOCK_TRANSFER |
SNDRV_PCM_INFO_INTERLEAVED |
+ SNDRV_PCM_INFO_RESUME |
SNDRV_PCM_INFO_PAUSE;
Actually you don't need to set SNDRV_PCM_INFO_RESUME.
This flag means that the driver supports the full resume procedure,
which isn't often the case; with this, the driver is supposed to
resume the stream exactly from the suspended position.
Most drivers don't set this but implement only the suspend-stop
action. Then the application (or the sound backend) will re-setup the
stream and restart accordingly.
@@ -309,6 +318,21 @@ static int virtsnd_pcm_trigger(struct snd_pcm_substream *substream, int command)
int rc;
switch (command) {
+ case SNDRV_PCM_TRIGGER_RESUME: {
+ /*
+ * We restart the substream by executing the standard command
+ * sequence.
+ */
+ rc = virtsnd_pcm_hw_params(substream, NULL);
+ if (rc)
+ return rc;
+
+ rc = virtsnd_pcm_prepare(substream);
+ if (rc)
+ return rc;
And this won't work at all unless nonatomic PCM ops.
thanks,
Takashi