Anton Yakovlev
2021-Jan-24 16:54 UTC
[PATCH v2 8/9] ALSA: virtio: introduce PCM channel map support
Enumerate all available PCM channel maps and create ALSA controls.
Signed-off-by: Anton Yakovlev <anton.yakovlev at 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
diff --git a/sound/virtio/Makefile b/sound/virtio/Makefile
index 09f485291285..2742bddb8874 100644
--- a/sound/virtio/Makefile
+++ b/sound/virtio/Makefile
@@ -4,6 +4,7 @@ obj-$(CONFIG_SND_VIRTIO) += virtio_snd.o
virtio_snd-objs := \
virtio_card.o \
+ virtio_chmap.o \
virtio_ctl_msg.o \
virtio_jack.o \
virtio_pcm.o \
diff --git a/sound/virtio/virtio_card.c b/sound/virtio/virtio_card.c
index 1dd709437208..fabf91fc1c9c 100644
--- a/sound/virtio/virtio_card.c
+++ b/sound/virtio/virtio_card.c
@@ -308,6 +308,10 @@ static int virtsnd_build_devs(struct virtio_snd *snd)
if (rc)
return rc;
+ rc = virtsnd_chmap_parse_cfg(snd);
+ if (rc)
+ return rc;
+
if (snd->njacks) {
rc = virtsnd_jack_build_devs(snd);
if (rc)
@@ -320,6 +324,12 @@ static int virtsnd_build_devs(struct virtio_snd *snd)
return rc;
}
+ if (snd->nchmaps) {
+ rc = virtsnd_chmap_build_devs(snd);
+ if (rc)
+ return rc;
+ }
+
return snd_card_register(snd->card);
}
@@ -438,6 +448,8 @@ static void virtsnd_remove(struct virtio_device *vdev)
if (stream->substreams)
devm_kfree(&vdev->dev, stream->substreams);
+ if (stream->chmaps)
+ devm_kfree(&vdev->dev, stream->chmaps);
}
devm_kfree(&vdev->dev, pcm);
@@ -449,6 +461,9 @@ static void virtsnd_remove(struct virtio_device *vdev)
if (snd->substreams)
devm_kfree(&vdev->dev, snd->substreams);
+ if (snd->chmaps)
+ devm_kfree(&vdev->dev, snd->chmaps);
+
devm_kfree(&vdev->dev, snd);
vdev->priv = NULL;
diff --git a/sound/virtio/virtio_card.h b/sound/virtio/virtio_card.h
index df4b0696e8c4..09c6e9ab80ca 100644
--- a/sound/virtio/virtio_card.h
+++ b/sound/virtio/virtio_card.h
@@ -52,6 +52,8 @@ struct virtio_snd_queue {
* @njacks: Number of jacks.
* @substreams: VirtIO PCM substreams.
* @nsubstreams: Number of PCM substreams.
+ * @chmaps: VirtIO channel maps.
+ * @nchmaps: Number of channel maps.
*/
struct virtio_snd {
struct virtio_device *vdev;
@@ -65,6 +67,8 @@ struct virtio_snd {
unsigned int njacks;
struct virtio_pcm_substream *substreams;
unsigned int nsubstreams;
+ struct virtio_snd_chmap_info *chmaps;
+ unsigned int nchmaps;
};
/* Message completion timeout in milliseconds (module parameter). */
@@ -110,4 +114,8 @@ int virtsnd_jack_build_devs(struct virtio_snd *snd);
void virtsnd_jack_event(struct virtio_snd *snd,
struct virtio_snd_event *event);
+int virtsnd_chmap_parse_cfg(struct virtio_snd *snd);
+
+int virtsnd_chmap_build_devs(struct virtio_snd *snd);
+
#endif /* VIRTIO_SND_CARD_H */
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 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Sound card driver for virtio
+ * Copyright (C) 2020 OpenSynergy GmbH
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/virtio_config.h>
+
+#include "virtio_card.h"
+
+/* VirtIO->ALSA channel position map */
+static const u8 g_v2a_position_map[] = {
+ [VIRTIO_SND_CHMAP_NONE] = SNDRV_CHMAP_UNKNOWN,
+ [VIRTIO_SND_CHMAP_NA] = SNDRV_CHMAP_NA,
+ [VIRTIO_SND_CHMAP_MONO] = SNDRV_CHMAP_MONO,
+ [VIRTIO_SND_CHMAP_FL] = SNDRV_CHMAP_FL,
+ [VIRTIO_SND_CHMAP_FR] = SNDRV_CHMAP_FR,
+ [VIRTIO_SND_CHMAP_RL] = SNDRV_CHMAP_RL,
+ [VIRTIO_SND_CHMAP_RR] = SNDRV_CHMAP_RR,
+ [VIRTIO_SND_CHMAP_FC] = SNDRV_CHMAP_FC,
+ [VIRTIO_SND_CHMAP_LFE] = SNDRV_CHMAP_LFE,
+ [VIRTIO_SND_CHMAP_SL] = SNDRV_CHMAP_SL,
+ [VIRTIO_SND_CHMAP_SR] = SNDRV_CHMAP_SR,
+ [VIRTIO_SND_CHMAP_RC] = SNDRV_CHMAP_RC,
+ [VIRTIO_SND_CHMAP_FLC] = SNDRV_CHMAP_FLC,
+ [VIRTIO_SND_CHMAP_FRC] = SNDRV_CHMAP_FRC,
+ [VIRTIO_SND_CHMAP_RLC] = SNDRV_CHMAP_RLC,
+ [VIRTIO_SND_CHMAP_RRC] = SNDRV_CHMAP_RRC,
+ [VIRTIO_SND_CHMAP_FLW] = SNDRV_CHMAP_FLW,
+ [VIRTIO_SND_CHMAP_FRW] = SNDRV_CHMAP_FRW,
+ [VIRTIO_SND_CHMAP_FLH] = SNDRV_CHMAP_FLH,
+ [VIRTIO_SND_CHMAP_FCH] = SNDRV_CHMAP_FCH,
+ [VIRTIO_SND_CHMAP_FRH] = SNDRV_CHMAP_FRH,
+ [VIRTIO_SND_CHMAP_TC] = SNDRV_CHMAP_TC,
+ [VIRTIO_SND_CHMAP_TFL] = SNDRV_CHMAP_TFL,
+ [VIRTIO_SND_CHMAP_TFR] = SNDRV_CHMAP_TFR,
+ [VIRTIO_SND_CHMAP_TFC] = SNDRV_CHMAP_TFC,
+ [VIRTIO_SND_CHMAP_TRL] = SNDRV_CHMAP_TRL,
+ [VIRTIO_SND_CHMAP_TRR] = SNDRV_CHMAP_TRR,
+ [VIRTIO_SND_CHMAP_TRC] = SNDRV_CHMAP_TRC,
+ [VIRTIO_SND_CHMAP_TFLC] = SNDRV_CHMAP_TFLC,
+ [VIRTIO_SND_CHMAP_TFRC] = SNDRV_CHMAP_TFRC,
+ [VIRTIO_SND_CHMAP_TSL] = SNDRV_CHMAP_TSL,
+ [VIRTIO_SND_CHMAP_TSR] = SNDRV_CHMAP_TSR,
+ [VIRTIO_SND_CHMAP_LLFE] = SNDRV_CHMAP_LLFE,
+ [VIRTIO_SND_CHMAP_RLFE] = SNDRV_CHMAP_RLFE,
+ [VIRTIO_SND_CHMAP_BC] = SNDRV_CHMAP_BC,
+ [VIRTIO_SND_CHMAP_BLC] = SNDRV_CHMAP_BLC,
+ [VIRTIO_SND_CHMAP_BRC] = SNDRV_CHMAP_BRC
+};
+
+/**
+ * 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];
+ else
+ stream = &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];
+ }
+ }
+
+ /* 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;
+}
diff --git a/sound/virtio/virtio_pcm.h b/sound/virtio/virtio_pcm.h
index fe467bc05d8b..a326b921b947 100644
--- a/sound/virtio/virtio_pcm.h
+++ b/sound/virtio/virtio_pcm.h
@@ -70,10 +70,14 @@ struct virtio_pcm_substream {
* struct virtio_pcm_stream - VirtIO PCM stream.
* @substreams: Virtio substreams belonging to the stream.
* @nsubstreams: Number of substreams.
+ * @chmaps: Kernel channel maps belonging to the stream.
+ * @nchmaps: Number of channel maps.
*/
struct virtio_pcm_stream {
struct virtio_pcm_substream **substreams;
unsigned int nsubstreams;
+ struct snd_pcm_chmap_elem *chmaps;
+ unsigned int nchmaps;
};
/**
--
2.30.0
Guennadi Liakhovetski
2021-Jan-26 09:22 UTC
[PATCH v2 8/9] ALSA: virtio: introduce PCM channel map support
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 at 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]; > + else > + stream = &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?> + > + /* 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; > +}
Anton Yakovlev
2021-Feb-01 23:21 UTC
[PATCH v2 8/9] ALSA: virtio: introduce PCM channel map support
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 at
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];
>> + else
>> + stream =
&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;
>> +}
>
--
Anton Yakovlev
Senior Software Engineer
OpenSynergy GmbH
Rotherstr. 20, 10245 Berlin
www.opensynergy.com