If a driver does not supply a drain operation for outputs, a default code
path will execute msleep(50). Especially for a virtual midi device
this severely limmits the throughput.
This implementation for the virtual midi driver simply flushes the output
workqueue.
Signed-off-by: Stefan Sauer <st.kost@xxxxxxxxx>
---
sound/core/seq/seq_virmidi.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/sound/core/seq/seq_virmidi.c b/sound/core/seq/seq_virmidi.c
index 4abc38c70cae..f5cae49500c8 100644
--- a/sound/core/seq/seq_virmidi.c
+++ b/sound/core/seq/seq_virmidi.c
@@ -262,6 +262,16 @@ static int snd_virmidi_output_close(struct snd_rawmidi_substream *substream)
return 0;
}
+/*
+ * drain output work queue
+ */
+static void snd_virmidi_output_drain(struct snd_rawmidi_substream *substream)
+{
+ struct snd_virmidi *vmidi = substream->runtime->private_data;
+
+ flush_work(&vmidi->output_work);
+}
+
/*
* subscribe callback - allow output to rawmidi device
*/
@@ -336,6 +346,7 @@ static const struct snd_rawmidi_ops snd_virmidi_output_ops = {
.open = snd_virmidi_output_open,
.close = snd_virmidi_output_close,
.trigger = snd_virmidi_output_trigger,
+ .drain = snd_virmidi_output_drain,
};
/*
--
2.34.1
