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 |