[PATCH 1/2] ALSA: aloop: Add support for the non-interleaved access mode
The current version of the loopback driver supports interleaved access mode only. This patch introduces support for the non-interleaved access mode. When in the interleaved mode, the 'copy_play_buf' function copies data from the playback to the capture buffer using one memcpy call. This call copies samples for multiple, interleaved channels. In the non-interleaved mode we have multiple channel buffers, so we have to perform multiple memcpy calls to copy samples channel after channel. Add new function called 'copy_play_buf_part_n', which copies a part of each channel buffer from playback to capture. Modify the 'copy_play_buf' to use the corresponding memory copy function(just memcpy / copy_play_buf_part_n) depending on the access mode. Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com> --- sound/drivers/aloop.c | 31 ++++++++++++++++++++++++++++--- 1 file changed, 28 insertions(+), 3 deletions(-) diff --git a/sound/drivers/aloop.c b/sound/drivers/aloop.c index a38e602b4fc6..ab116b1fed96 100644 --- a/sound/drivers/aloop.c +++ b/sound/drivers/aloop.c @@ -158,6 +158,9 @@ struct loopback_pcm { unsigned long last_jiffies; /* If jiffies timer is used */ struct timer_list timer; + + /* size of per channel buffer in case of non-interleaved access */ + unsigned int channel_buf_n; }; static struct platform_device *devices[SNDRV_CARDS]; @@ -335,7 +338,8 @@ static int loopback_check_format(struct loopback_cable *cable, int stream) substream->runtime; check = runtime->format != cruntime->format || runtime->rate != cruntime->rate || - runtime->channels != cruntime->channels; + runtime->channels != cruntime->channels || + runtime->access != cruntime->access; if (!check) return 0; if (stream == SNDRV_PCM_STREAM_CAPTURE) { @@ -472,6 +476,7 @@ static int loopback_prepare(struct snd_pcm_substream *substream) dpcm->buf_pos = 0; dpcm->pcm_buffer_size = frames_to_bytes(runtime, runtime->buffer_size); + dpcm->channel_buf_n = dpcm->pcm_buffer_size / runtime->channels; if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) { /* clear capture buffer */ dpcm->silent_size = dpcm->pcm_buffer_size; @@ -522,6 +527,22 @@ static void clear_capture_buf(struct loopback_pcm *dpcm, unsigned int bytes) } } +static void copy_play_buf_part_n(struct loopback_pcm *play, struct loopback_pcm *capt, + unsigned int size, unsigned int src_off, unsigned int dst_off) +{ + unsigned int channels = capt->substream->runtime->channels; + unsigned int size_p_ch = size / channels; + unsigned int src_off_ch = src_off / channels; + unsigned int dst_off_ch = dst_off / channels; + int i; + + for (i = 0; i < channels; i++) { + memcpy(capt->substream->runtime->dma_area + capt->channel_buf_n * i + dst_off_ch, + play->substream->runtime->dma_area + play->channel_buf_n * i + src_off_ch, + size_p_ch); + } +} + static void copy_play_buf(struct loopback_pcm *play, struct loopback_pcm *capt, unsigned int bytes) @@ -556,7 +577,11 @@ static void copy_play_buf(struct loopback_pcm *play, size = play->pcm_buffer_size - src_off; if (dst_off + size > capt->pcm_buffer_size) size = capt->pcm_buffer_size - dst_off; - memcpy(dst + dst_off, src + src_off, size); + if (runtime->access == SNDRV_PCM_ACCESS_RW_NONINTERLEAVED || + runtime->access == SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED) + copy_play_buf_part_n(play, capt, size, src_off, dst_off); + else + memcpy(dst + dst_off, src + src_off, size); capt->silent_size = 0; bytes -= size; if (!bytes) @@ -878,7 +903,7 @@ static const struct snd_pcm_hardware loopback_pcm_hardware = { .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_PAUSE | - SNDRV_PCM_INFO_RESUME), + SNDRV_PCM_INFO_RESUME | SNDRV_PCM_INFO_NONINTERLEAVED), .formats = (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE | SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S24_BE | SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_3BE | -- 2.34.1
Add new control element 'PCM Slave Access Mode' which shows the access mode (interleaved/non-interleaved) for the PCM playing device. Add corresponding control change notification calls. Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com> --- sound/drivers/aloop.c | 45 ++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 44 insertions(+), 1 deletion(-) diff --git a/sound/drivers/aloop.c b/sound/drivers/aloop.c index ab116b1fed96..e87dc67f33c6 100644 --- a/sound/drivers/aloop.c +++ b/sound/drivers/aloop.c @@ -119,11 +119,13 @@ struct loopback_setup { unsigned int rate_shift; snd_pcm_format_t format; unsigned int rate; + snd_pcm_access_t access; unsigned int channels; struct snd_ctl_elem_id active_id; struct snd_ctl_elem_id format_id; struct snd_ctl_elem_id rate_id; struct snd_ctl_elem_id channels_id; + struct snd_ctl_elem_id access_id; }; struct loopback { @@ -367,6 +369,11 @@ static int loopback_check_format(struct loopback_cable *cable, int stream) &setup->channels_id); setup->channels = runtime->channels; } + if (setup->access != runtime->access) { + snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, + &setup->access_id); + setup->access = runtime->access; + } } return 0; } @@ -1520,6 +1527,30 @@ static int loopback_channels_get(struct snd_kcontrol *kcontrol, return 0; } +static int loopback_access_info(struct snd_kcontrol *kcontrol, + struct snd_ctl_elem_info *uinfo) +{ + const char * const texts[] = {"Interleaved", "Non-interleaved"}; + + return snd_ctl_enum_info(uinfo, 1, ARRAY_SIZE(texts), texts); +} + +static int loopback_access_get(struct snd_kcontrol *kcontrol, + struct snd_ctl_elem_value *ucontrol) +{ + struct loopback *loopback = snd_kcontrol_chip(kcontrol); + snd_pcm_access_t access; + + mutex_lock(&loopback->cable_lock); + access = loopback->setup[kcontrol->id.subdevice][kcontrol->id.device].access; + + ucontrol->value.enumerated.item[0] = access == SNDRV_PCM_ACCESS_RW_NONINTERLEAVED || + access == SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED; + + mutex_unlock(&loopback->cable_lock); + return 0; +} + static const struct snd_kcontrol_new loopback_controls[] = { { .iface = SNDRV_CTL_ELEM_IFACE_PCM, @@ -1566,7 +1597,15 @@ static const struct snd_kcontrol_new loopback_controls[] = { .name = "PCM Slave Channels", .info = loopback_channels_info, .get = loopback_channels_get -} +}, +#define ACCESS_IDX 6 +{ + .access = SNDRV_CTL_ELEM_ACCESS_READ, + .iface = SNDRV_CTL_ELEM_IFACE_PCM, + .name = "PCM Slave Access Mode", + .info = loopback_access_info, + .get = loopback_access_get, +}, }; static int loopback_mixer_new(struct loopback *loopback, int notify) @@ -1587,6 +1626,7 @@ static int loopback_mixer_new(struct loopback *loopback, int notify) setup->notify = notify; setup->rate_shift = NO_PITCH; setup->format = SNDRV_PCM_FORMAT_S16_LE; + setup->access = SNDRV_PCM_ACCESS_RW_INTERLEAVED; setup->rate = 48000; setup->channels = 2; for (idx = 0; idx < ARRAY_SIZE(loopback_controls); @@ -1618,6 +1658,9 @@ static int loopback_mixer_new(struct loopback *loopback, int notify) case CHANNELS_IDX: setup->channels_id = kctl->id; break; + case ACCESS_IDX: + setup->access_id = kctl->id; + break; default: break; } -- 2.34.1
On 27. 09. 23 13:35, Ivan Orlov wrote:
Add new control element 'PCM Slave Access Mode' which shows the access mode (interleaved/non-interleaved) for the PCM playing device. Add corresponding control change notification calls.
Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Reviewed-by: Jaroslav Kysela <perex@perex.cz> Jaroslav -- Jaroslav Kysela <perex@perex.cz> Linux Sound Maintainer; ALSA Project; Red Hat, Inc.
On 27. 09. 23 13:35, Ivan Orlov wrote:
The current version of the loopback driver supports interleaved access mode only. This patch introduces support for the non-interleaved access mode.
When in the interleaved mode, the 'copy_play_buf' function copies data from the playback to the capture buffer using one memcpy call. This call copies samples for multiple, interleaved channels.
In the non-interleaved mode we have multiple channel buffers, so we have to perform multiple memcpy calls to copy samples channel after channel.
Add new function called 'copy_play_buf_part_n', which copies a part of each channel buffer from playback to capture. Modify the 'copy_play_buf' to use the corresponding memory copy function(just memcpy / copy_play_buf_part_n) depending on the access mode.
Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Nice extension. Thank you.
+static void copy_play_buf_part_n(struct loopback_pcm *play, struct loopback_pcm *capt, + unsigned int size, unsigned int src_off, unsigned int dst_off)
I would probably prefer to have dst,src,size arguments to follow memcpy, but it's really nitpicking. Reviewed-by: Jaroslav Kysela <perex@perex.cz> Jaroslav -- Jaroslav Kysela <perex@perex.cz> Linux Sound Maintainer; ALSA Project; Red Hat, Inc.
On 10/5/23 08:23, Jaroslav Kysela wrote:
On 27. 09. 23 13:35, Ivan Orlov wrote:
The current version of the loopback driver supports interleaved access mode only. This patch introduces support for the non-interleaved access mode.
When in the interleaved mode, the 'copy_play_buf' function copies data from the playback to the capture buffer using one memcpy call. This call copies samples for multiple, interleaved channels.
In the non-interleaved mode we have multiple channel buffers, so we have to perform multiple memcpy calls to copy samples channel after channel.
Add new function called 'copy_play_buf_part_n', which copies a part of each channel buffer from playback to capture. Modify the 'copy_play_buf' to use the corresponding memory copy function(just memcpy / copy_play_buf_part_n) depending on the access mode.
Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Nice extension. Thank you.
+static void copy_play_buf_part_n(struct loopback_pcm *play, struct loopback_pcm *capt, + unsigned int size, unsigned int src_off, unsigned int dst_off)
I would probably prefer to have dst,src,size arguments to follow memcpy, but it's really nitpicking.
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Jaroslav
Hi Jaroslav, Thank you for the review! I agree that parameters similar to the memcpy would look better than that, I'll keep it in mind when I send the next patch :) -- Kind regards, Ivan Orlov
On Wed, 27 Sep 2023 13:35:54 +0200, Ivan Orlov wrote:
The current version of the loopback driver supports interleaved access mode only. This patch introduces support for the non-interleaved access mode.
When in the interleaved mode, the 'copy_play_buf' function copies data from the playback to the capture buffer using one memcpy call. This call copies samples for multiple, interleaved channels.
In the non-interleaved mode we have multiple channel buffers, so we have to perform multiple memcpy calls to copy samples channel after channel.
Add new function called 'copy_play_buf_part_n', which copies a part of each channel buffer from playback to capture. Modify the 'copy_play_buf' to use the corresponding memory copy function(just memcpy / copy_play_buf_part_n) depending on the access mode.
Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Sorry for the late reaction, as I've been (still) off since the last week. Now applied both patches. Thanks. Takashi
On 10/6/23 09:52, Takashi Iwai wrote:
On Wed, 27 Sep 2023 13:35:54 +0200, Ivan Orlov wrote:
The current version of the loopback driver supports interleaved access mode only. This patch introduces support for the non-interleaved access mode.
When in the interleaved mode, the 'copy_play_buf' function copies data from the playback to the capture buffer using one memcpy call. This call copies samples for multiple, interleaved channels.
In the non-interleaved mode we have multiple channel buffers, so we have to perform multiple memcpy calls to copy samples channel after channel.
Add new function called 'copy_play_buf_part_n', which copies a part of each channel buffer from playback to capture. Modify the 'copy_play_buf' to use the corresponding memory copy function(just memcpy / copy_play_buf_part_n) depending on the access mode.
Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Sorry for the late reaction, as I've been (still) off since the last week.
Now applied both patches. Thanks.
Hi Takashi, No worries and thank you for applying both patches :) -- Kind regards, Ivan Orlov
participants (3)
-
Ivan Orlov -
Jaroslav Kysela -
Takashi Iwai