Am 04.09.23 um 12:34 schrieb Manos Pitsidianakis:
On Mon, 04 Sep 2023 13:26, Philippe Mathieu-Daudé <phi...@linaro.org>
wrote:
+/*
+ * AUD_* output callback.
+ *
+ * @data: VirtIOSoundPCMStream stream
+ * @available: number of bytes that can be written with AUD_write()
+ */
+static void virtio_snd_pcm_out_cb(void *data, int available)
+{
+ VirtIOSoundPCMStream *stream = data;
+ VirtIOSoundPCMBlock *block;
+ VirtIOSoundPCMBlock *next;
+ size_t size;
+
+ WITH_QEMU_LOCK_GUARD(&stream->queue_mutex) {
+ QSIMPLEQ_FOREACH_SAFE(block, &stream->queue, entry, next) {
+ for (;;) {
+ size = MIN(block->size, available);
+ size = AUD_write(stream->voice.out,
+ block->data + block->offset,
+ size);
If AUD_write() returns 0, is this an infinite loop?
Hm since we have available > 0 bytes this wouldn't theoretically
happen, but I see there are code paths that return 0 on bugs/failures,
I will add the check.
Before QEMU 8.0.0 it was possible that AUD_write() couldn't write the
last audio frame and sometimes 'available' was just miscalculated. Since
commit e1e6a6fcc9 ("audio: handle leftover audio frame from upsampling")
AUD_write() writes all 'available' bytes.
With best regards,
Volker
+ block->size -= size;
+ block->offset += size;
+ if (!block->size) {
+ virtqueue_push(block->vq,
+ block->elem,
+ sizeof(block->elem));
+ virtio_notify(VIRTIO_DEVICE(stream->s),
+ block->vq);
+ QSIMPLEQ_REMOVE_HEAD(&stream->queue, entry);
+ g_free(block);
+ available -= size;
+ break;
+ }
+
+ available -= size;
+ if (!available) {
+ break;
+ }
+ }
+ if (!available) {
+ break;
+ }
+ }
+ }
+}
+
+/*
+ * Flush all buffer data from this stream's queue into the driver's
virtual
+ * queue.
+ *
+ * @stream: VirtIOSoundPCMStream *stream
+ */
+static void virtio_snd_pcm_flush(VirtIOSoundPCMStream *stream)
+{
+ VirtIOSoundPCMBlock *block;
+ VirtIOSoundPCMBlock *next;
+
+ WITH_QEMU_LOCK_GUARD(&stream->queue_mutex) {
+ QSIMPLEQ_FOREACH_SAFE(block, &stream->queue, entry, next) {
+ AUD_write(stream->voice.out, block->data +
block->offset, block->size);
