Re: [RFC PATCH v2 3/3] ASoC: fsl_asrc_dma: Reuse the dma channel if available in Back-End
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
Re: [RFC PATCH v2 3/3] ASoC: fsl_asrc_dma: Reuse the dma channel if available in Back-End
On Fri, Jun 12, 2020 at 8:33 AM Nicolin Chen 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
> > ---
> > 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, >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;
> > +
Re: [RFC PATCH v2 3/3] ASoC: fsl_asrc_dma: Reuse the dma channel if available in Back-End
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
> ---
> 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, >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);
[RFC PATCH v2 3/3] ASoC: fsl_asrc_dma: Reuse the dma channel if available in Back-End
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
---
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, >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,
+
