| Message ID | 0473d4191ae04ab711d63c5c875e47f45f598137.1591783089.git.shengjiu.wang@nxp.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ASoC: fsl_asrc_dma: Reuse the dma channel if available in Back-End | expand |
On Wed, Jun 10, 2020 at 06:05:49PM +0800, Shengjiu Wang wrote: > 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 Since we only have dma_request call for back-end only: + * @req_dma_chan: flag to release back-end dma chan > 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 > @@ -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]; Should we use substream_be->stream or just substream->stream? And would be better to add these lines right before we really use tmp_chan because there's still some distance till it reaches that point. And would be better to have a line of comments too. > @@ -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; This is a bit confusing...though I finally got it :) So probably better to have a line of comments. > @@ -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. > + */ This sounds like a different issue and should be fixed separately? If you prefer not to, better to move this one to commit log, other than having a changelog here, in my opinion. Since it no longer uses get_dma_channel() for EDMA case, we should update the comments at the top as well. > + 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; > + } > } Now there are some duplicated lines between these if-else routines, so combining my previous comments, we can do (sample change, not tested): @@ -197,18 +199,29 @@ static int fsl_asrc_dma_hw_params(struct snd_soc_component *component, dma_cap_set(DMA_SLAVE, mask); dma_cap_set(DMA_CYCLIC, mask); + /* + * The Back-End device might have already requested a DMA channel, + * so try to reuse it first, and then request a new one upon NULL. + */ + component_be = snd_soc_lookup_component_nolocked(dev_be, SND_DMAENGINE_PCM_DRV_NAME); + if (component_be) // should probably error out if !component_be? + tmp_chan = be_chan = soc_component_to_pcm(component_be)->chan[substream->stream]; + if (!tmp_chan) + tmp_chan = dma_request_slave_channel(dev_be, tx ? "tx" : "rx"); + /* * An EDMA DEV_TO_DEV channel is fixed and bound with DMA event of each * peripheral, unlike SDMA channel that is allocated dynamically. So no - * need to configure dma_request and dma_request2, but get dma_chan via - * dma_request_slave_channel directly with dma name of Front-End device + * need to configure dma_request and dma_request2, but get dma_chan of + * Back-End device directly via dma_request_slave_channel. */ if (!asrc->use_edma) { /* Get DMA request of Back-End */ - tmp_chan = dma_request_slave_channel(dev_be, tx ? "tx" : "rx"); tmp_data = tmp_chan->private; pair->dma_data.dma_request = tmp_data->dma_request; - dma_release_channel(tmp_chan); + /* Do not release tmp_chan if we are reusing the Back-End one */ + if (!be_chan) + dma_release_channel(tmp_chan); /* Get DMA request of Front-End */ tmp_chan = asrc->get_dma_channel(pair, dir); @@ -220,9 +233,11 @@ 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 = true; } else { - pair->dma_chan[dir] = - asrc->get_dma_channel(pair, dir); + pair->dma_chan[dir] = tmp_chan; + /* Do not flag to release if we are reusing the Back-End one */ + pair->req_dma_chan = !be_chan; } if (!pair->dma_chan[dir]) { > @@ -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]); Why we only apply this to one direction?
On Fri, Jun 12, 2020 at 8:33 AM Nicolin Chen <nicoleotsuka@gmail.com> wrote: > > On Wed, Jun 10, 2020 at 06:05:49PM +0800, Shengjiu Wang wrote: > > 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 > > Since we only have dma_request call for back-end only: > + * @req_dma_chan: flag to release back-end dma chan I prefer to use the description "flag to release dev_to_dev chan" because we won't release the dma chan of the back-end. if the chan is from the back-end, it is owned by the back-end component. > > > 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 > > @@ -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]; > > Should we use substream_be->stream or just substream->stream? substream_be->stream should be better. > > And would be better to add these lines right before we really use > tmp_chan because there's still some distance till it reaches that > point. And would be better to have a line of comments too. ok. > > > @@ -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; > > This is a bit confusing...though I finally got it :) > So probably better to have a line of comments. ok. > > > @@ -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. > > + */ > > This sounds like a different issue and should be fixed separately? > If you prefer not to, better to move this one to commit log, other > than having a changelog here, in my opinion. ok, will move it in commit log. > > Since it no longer uses get_dma_channel() for EDMA case, we should > update the comments at the top as well. > > > + 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; > > + } > > } > > Now there are some duplicated lines between these if-else routines, so > combining my previous comments, we can do (sample change, not tested): ok, will try yours. > > @@ -197,18 +199,29 @@ static int fsl_asrc_dma_hw_params(struct snd_soc_component *component, > dma_cap_set(DMA_SLAVE, mask); > dma_cap_set(DMA_CYCLIC, mask); > > + /* > + * The Back-End device might have already requested a DMA channel, > + * so try to reuse it first, and then request a new one upon NULL. > + */ > + component_be = snd_soc_lookup_component_nolocked(dev_be, SND_DMAENGINE_PCM_DRV_NAME); > + if (component_be) // should probably error out if !component_be? > + tmp_chan = be_chan = soc_component_to_pcm(component_be)->chan[substream->stream]; > + if (!tmp_chan) > + tmp_chan = dma_request_slave_channel(dev_be, tx ? "tx" : "rx"); > + > /* > * An EDMA DEV_TO_DEV channel is fixed and bound with DMA event of each > * peripheral, unlike SDMA channel that is allocated dynamically. So no > - * need to configure dma_request and dma_request2, but get dma_chan via > - * dma_request_slave_channel directly with dma name of Front-End device > + * need to configure dma_request and dma_request2, but get dma_chan of > + * Back-End device directly via dma_request_slave_channel. > */ > if (!asrc->use_edma) { > /* Get DMA request of Back-End */ > - tmp_chan = dma_request_slave_channel(dev_be, tx ? "tx" : "rx"); > tmp_data = tmp_chan->private; > pair->dma_data.dma_request = tmp_data->dma_request; > - dma_release_channel(tmp_chan); > + /* Do not release tmp_chan if we are reusing the Back-End one */ > + if (!be_chan) > + dma_release_channel(tmp_chan); > > /* Get DMA request of Front-End */ > tmp_chan = asrc->get_dma_channel(pair, dir); > @@ -220,9 +233,11 @@ 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 = true; > } else { > - pair->dma_chan[dir] = > - asrc->get_dma_channel(pair, dir); > + pair->dma_chan[dir] = tmp_chan; > + /* Do not flag to release if we are reusing the Back-End one */ > + pair->req_dma_chan = !be_chan; > } > > if (!pair->dma_chan[dir]) { > > > @@ -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]); > > Why we only apply this to one direction? if the chan is from the back-end, it is owned by the back-end component, so it should be released by the back-end component, not here. That's why I added the flag "req_dma_chan".
On Fri, Jun 12, 2020 at 10:17:08AM +0800, Shengjiu Wang wrote: > > > diff --git a/sound/soc/fsl/fsl_asrc_common.h b/sound/soc/fsl/fsl_asrc_common.h > > > + * @req_dma_chan_dev_to_dev: flag for release dev_to_dev chan > > > > Since we only have dma_request call for back-end only: > > + * @req_dma_chan: flag to release back-end dma chan > > I prefer to use the description "flag to release dev_to_dev chan" > because we won't release the dma chan of the back-end. if the chan > is from the back-end, it is owned by the back-end component. TBH, it just looks too long. But I wouldn't have problem if you insist so. > > > @@ -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]); > > > > Why we only apply this to one direction? > > if the chan is from the back-end, it is owned by the back-end > component, so it should be released by the back-end component, > not here. That's why I added the flag "req_dma_chan". Ah...I forgot the IN and OUT is for front-end and back-end. The naming isn't very good indeed. Probably we should add a line of comments somewhere as a reminder. Thanks
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; }
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(-)