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 <[email protected]>
---
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
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 <[email protected]>
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 <[email protected]>
Jaroslav
--
Jaroslav Kysela <[email protected]>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.
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 <[email protected]>
Sorry for the late reaction, as I've been (still) off since the last
week.
Now applied both patches. Thanks.
Takashi
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 <[email protected]>
>
> 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 <[email protected]>
>
> 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 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 <[email protected]>
>
> 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