ACP->SYSMEM DMA happens at every I2S->SYSMEM period completion. Thus, there is delay of x frames till I2S->SYSMEM reaches a period length. This delay is communicated to user space.
Signed-off-by: Akshu Agrawal akshu.agrawal@amd.com --- sound/soc/amd/acp-pcm-dma.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-)
diff --git a/sound/soc/amd/acp-pcm-dma.c b/sound/soc/amd/acp-pcm-dma.c index 6240a77..c24611c 100644 --- a/sound/soc/amd/acp-pcm-dma.c +++ b/sound/soc/amd/acp-pcm-dma.c @@ -922,6 +922,10 @@ static int acp_dma_hw_params(struct snd_pcm_substream *substream, rtd->destination = FROM_BLUETOOTH; rtd->dma_dscr_idx_1 = CAPTURE_START_DMA_DESCR_CH10; rtd->dma_dscr_idx_2 = CAPTURE_START_DMA_DESCR_CH11; + rtd->byte_cnt_high_reg_offset = + mmACP_I2S_BT_RECEIVE_BYTE_CNT_HIGH; + rtd->byte_cnt_low_reg_offset = + mmACP_I2S_BT_RECEIVE_BYTE_CNT_LOW; rtd->dma_curr_dscr = mmACP_DMA_CUR_DSCR_11; rtd->cur_trans_cnt = mmACP_DMA_CUR_TRANS_CNT_11; rtd->end_dma_dscr = CAPTURE_END_DMA_DESCR_CH10; @@ -944,6 +948,10 @@ static int acp_dma_hw_params(struct snd_pcm_substream *substream, rtd->destination = FROM_ACP_I2S_1; rtd->dma_dscr_idx_1 = CAPTURE_START_DMA_DESCR_CH14; rtd->dma_dscr_idx_2 = CAPTURE_START_DMA_DESCR_CH15; + rtd->byte_cnt_high_reg_offset = + mmACP_I2S_RECEIVED_BYTE_CNT_HIGH; + rtd->byte_cnt_low_reg_offset = + mmACP_I2S_RECEIVED_BYTE_CNT_LOW; rtd->dma_curr_dscr = mmACP_DMA_CUR_DSCR_15; rtd->cur_trans_cnt = mmACP_DMA_CUR_TRANS_CNT_15; rtd->end_dma_dscr = CAPTURE_END_DMA_DESCR_CH14; @@ -1002,7 +1010,7 @@ static snd_pcm_uframes_t acp_dma_pointer(struct snd_pcm_substream *substream) u64 bytescount = 0; u32 dma_count = 0; u16 dscr; - u32 period_bytes; + u32 period_bytes, delay;
struct snd_pcm_runtime *runtime = substream->runtime; struct audio_substream_data *rtd = runtime->private_data; @@ -1011,6 +1019,10 @@ static snd_pcm_uframes_t acp_dma_pointer(struct snd_pcm_substream *substream) return -EINVAL;
buffersize = frames_to_bytes(runtime, runtime->buffer_size); + bytescount = acp_get_byte_count(rtd); + if (bytescount > rtd->bytescount) + bytescount -= rtd->bytescount; + if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) { period_bytes = frames_to_bytes(runtime, runtime->period_size); dscr = acp_reg_read(rtd->acp_mmio, rtd->dma_curr_dscr); @@ -1018,10 +1030,9 @@ static snd_pcm_uframes_t acp_dma_pointer(struct snd_pcm_substream *substream) if (dscr == rtd->end_dma_dscr) dma_count += period_bytes; pos = dma_count % buffersize; + delay = do_div(bytescount, period_bytes); + runtime->delay = bytes_to_frames(runtime, delay); } else { - bytescount = acp_get_byte_count(rtd); - if (bytescount > rtd->bytescount) - bytescount -= rtd->bytescount; pos = do_div(bytescount, buffersize); } return bytes_to_frames(runtime, pos);