On 26.01.2021 10:22, Guennadi Liakhovetski wrote:
CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe.
On Sun, 24 Jan 2021, Anton Yakovlev wrote:
Enumerate all available PCM channel maps and create ALSA controls.
Signed-off-by: Anton Yakovlev anton.yakovlev@opensynergy.com
sound/virtio/Makefile | 1 + sound/virtio/virtio_card.c | 15 +++ sound/virtio/virtio_card.h | 8 ++ sound/virtio/virtio_chmap.c | 237 ++++++++++++++++++++++++++++++++++++ sound/virtio/virtio_pcm.h | 4 + 5 files changed, 265 insertions(+) create mode 100644 sound/virtio/virtio_chmap.c
[snip]
diff --git a/sound/virtio/virtio_chmap.c b/sound/virtio/virtio_chmap.c new file mode 100644 index 000000000000..8a2ddc4dcffb --- /dev/null +++ b/sound/virtio/virtio_chmap.c @@ -0,0 +1,237 @@
[snip]
+/**
- virtsnd_chmap_parse_cfg() - Parse the channel map configuration.
- @snd: VirtIO sound device.
- This function is called during initial device initialization.
- Context: Any context that permits to sleep.
- Return: 0 on success, -errno on failure.
- */
+int virtsnd_chmap_parse_cfg(struct virtio_snd *snd) +{
struct virtio_device *vdev = snd->vdev;unsigned int i;int rc;virtio_cread(vdev, struct virtio_snd_config, chmaps,&snd->nchmaps);
if (!snd->nchmaps)return 0;snd->chmaps = devm_kcalloc(&vdev->dev, snd->nchmaps,sizeof(*snd->chmaps), GFP_KERNEL);if (!snd->chmaps)return -ENOMEM;rc = virtsnd_ctl_query_info(snd, VIRTIO_SND_R_CHMAP_INFO, 0,snd->nchmaps, sizeof(*snd->chmaps),snd->chmaps);if (rc)return rc;/* Count the number of channel maps per each PCM device/stream. */for (i = 0; i < snd->nchmaps; ++i) {struct virtio_snd_chmap_info *info = &snd->chmaps[i];unsigned int nid = le32_to_cpu(info->hdr.hda_fn_nid);struct virtio_pcm *pcm;struct virtio_pcm_stream *stream;pcm = virtsnd_pcm_find_or_create(snd, nid);if (IS_ERR(pcm))return PTR_ERR(pcm);switch (info->direction) {case VIRTIO_SND_D_OUTPUT: {stream = &pcm->streams[SNDRV_PCM_STREAM_PLAYBACK];break;}case VIRTIO_SND_D_INPUT: {stream = &pcm->streams[SNDRV_PCM_STREAM_CAPTURE];break;}default: {dev_err(&vdev->dev,"chmap #%u: unknown direction (%u)\n", i,info->direction);return -EINVAL;}}stream->nchmaps++;}return 0;+}
+/**
- virtsnd_chmap_add_ctls() - Create an ALSA control for channel maps.
- @pcm: ALSA PCM device.
- @direction: PCM stream direction (SNDRV_PCM_STREAM_XXX).
- @stream: VirtIO PCM stream.
- Context: Any context.
- Return: 0 on success, -errno on failure.
- */
+static int virtsnd_chmap_add_ctls(struct snd_pcm *pcm, int direction,
struct virtio_pcm_stream *stream)+{
unsigned int i;int max_channels = 0;for (i = 0; i < stream->nchmaps; i++)if (max_channels < stream->chmaps[i].channels)max_channels = stream->chmaps[i].channels;return snd_pcm_add_chmap_ctls(pcm, direction, stream->chmaps,max_channels, 0, NULL);+}
+/**
- virtsnd_chmap_build_devs() - Build ALSA controls for channel maps.
- @snd: VirtIO sound device.
- Context: Any context.
- Return: 0 on success, -errno on failure.
- */
+int virtsnd_chmap_build_devs(struct virtio_snd *snd) +{
struct virtio_device *vdev = snd->vdev;struct virtio_pcm *pcm;struct virtio_pcm_stream *stream;unsigned int i;int rc;/* Allocate channel map elements per each PCM device/stream. */list_for_each_entry(pcm, &snd->pcm_list, list) {for (i = 0; i < ARRAY_SIZE(pcm->streams); ++i) {stream = &pcm->streams[i];if (!stream->nchmaps)continue;stream->chmaps = devm_kcalloc(&vdev->dev,stream->nchmaps + 1,sizeof(*stream->chmaps),
GFP_KERNEL);if (!stream->chmaps)return -ENOMEM;stream->nchmaps = 0;}}/* Initialize channel maps per each PCM device/stream. */for (i = 0; i < snd->nchmaps; ++i) {struct virtio_snd_chmap_info *info = &snd->chmaps[i];unsigned int nid = le32_to_cpu(info->hdr.hda_fn_nid);unsigned int channels = info->channels;unsigned int ch;struct snd_pcm_chmap_elem *chmap;pcm = virtsnd_pcm_find(snd, nid);if (IS_ERR(pcm))return PTR_ERR(pcm);if (info->direction == VIRTIO_SND_D_OUTPUT)stream = &pcm->streams[SNDRV_PCM_STREAM_PLAYBACK];elsestream = &pcm->streams[SNDRV_PCM_STREAM_CAPTURE];chmap = &stream->chmaps[stream->nchmaps++];if (channels > ARRAY_SIZE(chmap->map))channels = ARRAY_SIZE(chmap->map);chmap->channels = channels;for (ch = 0; ch < channels; ++ch) {u8 position = info->positions[ch];if (position >= ARRAY_SIZE(g_v2a_position_map))return -EINVAL;chmap->map[ch] = g_v2a_position_map[position];}}You enter this function after virtsnd_chmap_parse_cfg() has run. And virtsnd_chmap_parse_cfg() has already found or created all the PCMs and counted channel maps - the same way as you do in the above loop. Wouldn't it be enough to reuse the result of that counting and avoid re-counting here?
If I understood your question right, then... it's not re-counting here. :) It's just a referencing to each channel map for each stream in one by one manner.
/* Create an ALSA control per each PCM device/stream. */list_for_each_entry(pcm, &snd->pcm_list, list) {if (!pcm->pcm)continue;for (i = 0; i < ARRAY_SIZE(pcm->streams); ++i) {stream = &pcm->streams[i];if (!stream->nchmaps)continue;rc = virtsnd_chmap_add_ctls(pcm->pcm, i, stream);if (rc)return rc;}}return 0;+}