2021-03-04 06:36:30

by Anton Yakovlev

[permalink] [raw]
Subject: [PATCH v7 9/9] ALSA: virtio: introduce device suspend/resume support

All running PCM substreams are stopped on device suspend and restarted
on device resume.

Signed-off-by: Anton Yakovlev <[email protected]>
---
sound/virtio/virtio_card.c | 56 +++++++++++++++++++++++++++++++++++
sound/virtio/virtio_pcm.h | 3 ++
sound/virtio/virtio_pcm_ops.c | 33 ++++++++++++++++-----
3 files changed, 85 insertions(+), 7 deletions(-)

diff --git a/sound/virtio/virtio_card.c b/sound/virtio/virtio_card.c
index 1c03fcc41c3b..ae9128063917 100644
--- a/sound/virtio/virtio_card.c
+++ b/sound/virtio/virtio_card.c
@@ -362,6 +362,58 @@ 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;
+ unsigned int i;
+
+ virtsnd_disable_event_vq(snd);
+ virtsnd_ctl_msg_cancel_all(snd);
+
+ vdev->config->del_vqs(vdev);
+ vdev->config->reset(vdev);
+
+ for (i = 0; i < snd->nsubstreams; ++i)
+ cancel_work_sync(&snd->substreams[i].elapsed_period);
+
+ kfree(snd->event_msgs);
+ snd->event_msgs = NULL;
+
+ return 0;
+}
+
+/**
+ * virtsnd_restore() - Resume device.
+ * @vdev: VirtIO parent device.
+ *
+ * Context: Any context.
+ * Return: 0 on success, -errno on failure.
+ */
+static int virtsnd_restore(struct virtio_device *vdev)
+{
+ struct virtio_snd *snd = vdev->priv;
+ int rc;
+
+ rc = virtsnd_find_vqs(snd);
+ if (rc)
+ return rc;
+
+ virtio_device_ready(vdev);
+
+ virtsnd_enable_event_vq(snd);
+
+ return 0;
+}
+#endif /* CONFIG_PM_SLEEP */
+
static const struct virtio_device_id id_table[] = {
{ VIRTIO_ID_SOUND, VIRTIO_DEV_ANY_ID },
{ 0 },
@@ -374,6 +426,10 @@ static struct virtio_driver virtsnd_driver = {
.validate = virtsnd_validate,
.probe = virtsnd_probe,
.remove = virtsnd_remove,
+#ifdef CONFIG_PM_SLEEP
+ .freeze = virtsnd_freeze,
+ .restore = virtsnd_restore,
+#endif
};

static int __init init(void)
diff --git a/sound/virtio/virtio_pcm.h b/sound/virtio/virtio_pcm.h
index 1353fdc9bd69..062eb8e8f2cf 100644
--- a/sound/virtio/virtio_pcm.h
+++ b/sound/virtio/virtio_pcm.h
@@ -31,6 +31,8 @@ struct virtio_pcm_msg;
* @xfer_xrun: Data underflow/overflow state (0 - no xrun, 1 - xrun).
* @stopped: True if the substream is stopped and must be released on the device
* side.
+ * @suspended: True if the substream is suspended and must be reconfigured on
+ * the device side at resume.
* @msgs: Allocated I/O messages.
* @nmsgs: Number of allocated I/O messages.
* @msg_last_enqueued: Index of the last I/O message added to the virtqueue.
@@ -52,6 +54,7 @@ struct virtio_pcm_substream {
bool xfer_enabled;
bool xfer_xrun;
bool stopped;
+ bool suspended;
struct virtio_pcm_msg **msgs;
unsigned int nmsgs;
int msg_last_enqueued;
diff --git a/sound/virtio/virtio_pcm_ops.c b/sound/virtio/virtio_pcm_ops.c
index 0682a2df6c8c..f8bfb87624be 100644
--- a/sound/virtio/virtio_pcm_ops.c
+++ b/sound/virtio/virtio_pcm_ops.c
@@ -115,6 +115,7 @@ static int virtsnd_pcm_open(struct snd_pcm_substream *substream)
SNDRV_PCM_HW_PARAM_PERIODS);

vss->stopped = !!virtsnd_pcm_msg_pending_num(vss);
+ vss->suspended = false;

/*
* If the substream has already been used, then the I/O queue may be in
@@ -272,16 +273,31 @@ static int virtsnd_pcm_prepare(struct snd_pcm_substream *substream)
struct virtio_device *vdev = vss->snd->vdev;
struct virtio_snd_msg *msg;

- if (virtsnd_pcm_msg_pending_num(vss)) {
- dev_err(&vdev->dev, "SID %u: invalid I/O queue state\n",
- vss->sid);
- return -EBADFD;
+ if (!vss->suspended) {
+ if (virtsnd_pcm_msg_pending_num(vss)) {
+ dev_err(&vdev->dev, "SID %u: invalid I/O queue state\n",
+ vss->sid);
+ return -EBADFD;
+ }
+
+ vss->buffer_bytes = snd_pcm_lib_buffer_bytes(substream);
+ vss->hw_ptr = 0;
+ vss->msg_last_enqueued = -1;
+ } else {
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ unsigned int buffer_bytes = snd_pcm_lib_buffer_bytes(substream);
+ unsigned int period_bytes = snd_pcm_lib_period_bytes(substream);
+ int rc;
+
+ rc = virtsnd_pcm_dev_set_params(vss, buffer_bytes, period_bytes,
+ runtime->channels,
+ runtime->format, runtime->rate);
+ if (rc)
+ return rc;
}

- vss->buffer_bytes = snd_pcm_lib_buffer_bytes(substream);
- vss->hw_ptr = 0;
vss->xfer_xrun = false;
- vss->msg_last_enqueued = -1;
+ vss->suspended = false;
vss->msg_count = 0;

msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_PREPARE,
@@ -336,6 +352,9 @@ static int virtsnd_pcm_trigger(struct snd_pcm_substream *substream, int command)
}

return virtsnd_ctl_msg_send_sync(snd, msg);
+ case SNDRV_PCM_TRIGGER_SUSPEND:
+ vss->suspended = true;
+ fallthrough;
case SNDRV_PCM_TRIGGER_STOP:
vss->stopped = true;
fallthrough;
--
2.30.1