The dma channel has been requested by Back-End cpu dai driver already. If fsl_asrc_dma requests dma chan with same dma:tx symlink, then there will be below warning with SDMA.
[ 48.174236] fsl-esai-dai 2024000.esai: Cannot create DMA dma:tx symlink
or with EDMA the request operation will fail for EDMA channel can only be requested once.
So If we can reuse the dma channel of Back-End, then the issue can be fixed.
In order to get the dma channel which is already requested in Back-End. we use the exported two functions (snd_soc_lookup_component_nolocked and soc_component_to_pcm). If we can get the dma channel, then reuse it, if can't, then request a new one.
Signed-off-by: Shengjiu Wang shengjiu.wang@nxp.com --- sound/soc/fsl/fsl_asrc_common.h | 2 ++ sound/soc/fsl/fsl_asrc_dma.c | 52 +++++++++++++++++++++++++-------- 2 files changed, 42 insertions(+), 12 deletions(-)
diff --git a/sound/soc/fsl/fsl_asrc_common.h b/sound/soc/fsl/fsl_asrc_common.h index 77665b15c8db..09512bc79b80 100644 --- a/sound/soc/fsl/fsl_asrc_common.h +++ b/sound/soc/fsl/fsl_asrc_common.h @@ -32,6 +32,7 @@ enum asrc_pair_index { * @dma_chan: inputer and output DMA channels * @dma_data: private dma data * @pos: hardware pointer position + * @req_dma_chan_dev_to_dev: flag for release dev_to_dev chan * @private: pair private area */ struct fsl_asrc_pair { @@ -45,6 +46,7 @@ struct fsl_asrc_pair { struct dma_chan *dma_chan[2]; struct imx_dma_data dma_data; unsigned int pos; + bool req_dma_chan_dev_to_dev;
void *private; }; diff --git a/sound/soc/fsl/fsl_asrc_dma.c b/sound/soc/fsl/fsl_asrc_dma.c index d6a3fc5f87e5..5ecb77d466d3 100644 --- a/sound/soc/fsl/fsl_asrc_dma.c +++ b/sound/soc/fsl/fsl_asrc_dma.c @@ -133,6 +133,7 @@ static int fsl_asrc_dma_hw_params(struct snd_soc_component *component, bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK; struct snd_dmaengine_dai_dma_data *dma_params_fe = NULL; struct snd_dmaengine_dai_dma_data *dma_params_be = NULL; + struct dma_chan *tmp_chan = NULL, *tmp_chan_new = NULL; struct snd_pcm_runtime *runtime = substream->runtime; struct fsl_asrc_pair *pair = runtime->private_data; struct fsl_asrc *asrc = pair->asrc; @@ -142,7 +143,6 @@ static int fsl_asrc_dma_hw_params(struct snd_soc_component *component, int stream = substream->stream; struct imx_dma_data *tmp_data; struct snd_soc_dpcm *dpcm; - struct dma_chan *tmp_chan; struct device *dev_be; u8 dir = tx ? OUT : IN; dma_cap_mask_t mask; @@ -152,6 +152,7 @@ static int fsl_asrc_dma_hw_params(struct snd_soc_component *component, for_each_dpcm_be(rtd, stream, dpcm) { struct snd_soc_pcm_runtime *be = dpcm->be; struct snd_pcm_substream *substream_be; + struct snd_soc_component *component_be; struct snd_soc_dai *dai = asoc_rtd_to_cpu(be, 0);
if (dpcm->fe != rtd) @@ -160,6 +161,9 @@ static int fsl_asrc_dma_hw_params(struct snd_soc_component *component, substream_be = snd_soc_dpcm_get_substream(be, stream); dma_params_be = snd_soc_dai_get_dma_data(dai, substream_be); dev_be = dai->dev; + component_be = snd_soc_lookup_component_nolocked(dev_be, SND_DMAENGINE_PCM_DRV_NAME); + if (component_be) + tmp_chan = soc_component_to_pcm(component_be)->chan[substream->stream]; break; }
@@ -205,10 +209,14 @@ static int fsl_asrc_dma_hw_params(struct snd_soc_component *component, */ if (!asrc->use_edma) { /* Get DMA request of Back-End */ - tmp_chan = dma_request_slave_channel(dev_be, tx ? "tx" : "rx"); + if (!tmp_chan) { + tmp_chan_new = dma_request_slave_channel(dev_be, tx ? "tx" : "rx"); + tmp_chan = tmp_chan_new; + } tmp_data = tmp_chan->private; pair->dma_data.dma_request = tmp_data->dma_request; - dma_release_channel(tmp_chan); + if (tmp_chan_new) + dma_release_channel(tmp_chan_new);
/* Get DMA request of Front-End */ tmp_chan = asrc->get_dma_channel(pair, dir); @@ -220,9 +228,26 @@ static int fsl_asrc_dma_hw_params(struct snd_soc_component *component,
pair->dma_chan[dir] = dma_request_channel(mask, filter, &pair->dma_data); + pair->req_dma_chan_dev_to_dev = true; } else { - pair->dma_chan[dir] = - asrc->get_dma_channel(pair, dir); + /* + * With EDMA, there is two dma channels can be used for p2p, + * one is from ASRC, one is from another peripheral + * (ESAI or SAI). Previously we select the dma channel of ASRC, + * but find an issue for ideal ratio case, there is no control + * for data copy speed, the speed is faster than sample + * frequency. + * + * So we switch to use dma channel of peripheral (ESAI or SAI), + * that copy speed of DMA is controlled by data consumption + * speed in the peripheral FIFO. + */ + pair->req_dma_chan_dev_to_dev = false; + pair->dma_chan[dir] = tmp_chan; + if (!pair->dma_chan[dir]) { + pair->dma_chan[dir] = dma_request_slave_channel(dev_be, tx ? "tx" : "rx"); + pair->req_dma_chan_dev_to_dev = true; + } }
if (!pair->dma_chan[dir]) { @@ -261,7 +286,8 @@ static int fsl_asrc_dma_hw_params(struct snd_soc_component *component, ret = dmaengine_slave_config(pair->dma_chan[dir], &config_be); if (ret) { dev_err(dev, "failed to config DMA channel for Back-End\n"); - dma_release_channel(pair->dma_chan[dir]); + if (pair->req_dma_chan_dev_to_dev) + dma_release_channel(pair->dma_chan[dir]); return ret; }
@@ -273,19 +299,21 @@ static int fsl_asrc_dma_hw_params(struct snd_soc_component *component, static int fsl_asrc_dma_hw_free(struct snd_soc_component *component, struct snd_pcm_substream *substream) { + bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK; struct snd_pcm_runtime *runtime = substream->runtime; struct fsl_asrc_pair *pair = runtime->private_data; + u8 dir = tx ? OUT : IN;
snd_pcm_set_runtime_buffer(substream, NULL);
- if (pair->dma_chan[IN]) - dma_release_channel(pair->dma_chan[IN]); + if (pair->dma_chan[!dir]) + dma_release_channel(pair->dma_chan[!dir]);
- if (pair->dma_chan[OUT]) - dma_release_channel(pair->dma_chan[OUT]); + if (pair->dma_chan[dir] && pair->req_dma_chan_dev_to_dev) + dma_release_channel(pair->dma_chan[dir]);
- pair->dma_chan[IN] = NULL; - pair->dma_chan[OUT] = NULL; + pair->dma_chan[!dir] = NULL; + pair->dma_chan[dir] = NULL;
return 0; }