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 --- v2: moved reading of bytes transfered from I2S->ACP to get more accurate delay information. sound/soc/amd/acp-pcm-dma.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/sound/soc/amd/acp-pcm-dma.c b/sound/soc/amd/acp-pcm-dma.c index 32f27c5..e359938 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; adata->capture_i2sbt_stream = substream; break; @@ -942,6 +946,10 @@ 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; adata->capture_i2ssp_stream = substream; } @@ -997,7 +1005,7 @@ static snd_pcm_uframes_t acp_dma_pointer(struct snd_pcm_substream *substream) u32 pos = 0; u64 bytescount = 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; @@ -1012,6 +1020,11 @@ static snd_pcm_uframes_t acp_dma_pointer(struct snd_pcm_substream *substream) pos = period_bytes; else pos = 0; + bytescount = acp_get_byte_count(rtd); + if (bytescount > rtd->bytescount) + bytescount -= rtd->bytescount; + delay = do_div(bytescount, period_bytes); + runtime->delay = bytes_to_frames(runtime, delay); } else { buffersize = frames_to_bytes(runtime, runtime->buffer_size); bytescount = acp_get_byte_count(rtd);