One more thing I missed yesterday:
On Mon, 25 Jan 2021, Guennadi Liakhovetski wrote:
On Sun, 24 Jan 2021, Anton Yakovlev wrote:
Introduce the operators required for the operation of substreams.
Signed-off-by: Anton Yakovlev anton.yakovlev@opensynergy.com
sound/virtio/Makefile | 3 +- sound/virtio/virtio_pcm.c | 5 +- sound/virtio/virtio_pcm.h | 2 + sound/virtio/virtio_pcm_ops.c | 513 ++++++++++++++++++++++++++++++++++ 4 files changed, 521 insertions(+), 2 deletions(-) create mode 100644 sound/virtio/virtio_pcm_ops.c
[snip]
diff --git a/sound/virtio/virtio_pcm_ops.c b/sound/virtio/virtio_pcm_ops.c new file mode 100644 index 000000000000..19882777fcd6 --- /dev/null +++ b/sound/virtio/virtio_pcm_ops.c @@ -0,0 +1,513 @@
[snip]
+/**
- virtsnd_pcm_release() - Release the PCM substream on the device side.
- @substream: VirtIO substream.
- Context: Any context that permits to sleep.
- Return: 0 on success, -errno on failure.
- */
+static inline bool virtsnd_pcm_released(struct virtio_pcm_substream *substream) +{
- /*
* The spec states that upon receipt of the RELEASE command "thedevice
* MUST complete all pending I/O messages for the specified streamID".
* Thus, we consider the absence of I/O messages in the queue as an* indication that the substream has been released.*/- return atomic_read(&substream->msg_count) == 0;
Also here having it atomic doesn't really seem to help. This just means, that at some point of time it was == 0.
+}
+static int virtsnd_pcm_release(struct virtio_pcm_substream *substream)
kernel-doc missing
+{
- struct virtio_snd *snd = substream->snd;
- struct virtio_snd_msg *msg;
- unsigned int js = msecs_to_jiffies(msg_timeout_ms);
- int rc;
- msg = virtsnd_pcm_ctl_msg_alloc(substream, VIRTIO_SND_R_PCM_RELEASE,
GFP_KERNEL);- if (IS_ERR(msg))
return PTR_ERR(msg);- rc = virtsnd_ctl_msg_send_sync(snd, msg);
- if (rc)
return rc;- return wait_event_interruptible_timeout(substream->msg_empty,
virtsnd_pcm_released(substream),js);
wait_event_interruptible_timeout() will return a positive number in success cases, 0 means a timeout and condition still false. Whereas when you call this function you interpret 0 as success and you expect any != 0 to be a negative error. Wondering how this worked during your tests?
Thanks Guennadi