The issue log is:

[ 48.021506] CPU: 0 PID: 664 Comm: aplay Not tainted 5.7.0-rc1-13120-g12b434cbbea0 #343 [ 48.031063] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) [ 48.037638] [<c0110dd8>] (unwind_backtrace) from [<c010b8ec>] (show_stack+0x10/0x14) [ 48.045413] [<c010b8ec>] (show_stack) from [<c0557fc0>] (dump_stack+0xe4/0x118) [ 48.052757] [<c0557fc0>] (dump_stack) from [<c032aeb4>] (sysfs_warn_dup+0x50/0x64) [ 48.060357] [<c032aeb4>] (sysfs_warn_dup) from [<c032b1a8>] (sysfs_do_create_link_sd+0xc8/0xd4) [ 48.069086] [<c032b1a8>] (sysfs_do_create_link_sd) from [<c05dc668>] (dma_request_chan+0xb0/0x210) [ 48.078068] [<c05dc668>] (dma_request_chan) from [<c05dc7d0>] (dma_request_slave_channel+0x8/0x14) [ 48.087060] [<c05dc7d0>] (dma_request_slave_channel) from [<c09d5cd4>] (fsl_asrc_dma_hw_params+0x1dc/0x434) [ 48.096831] [<c09d5cd4>] (fsl_asrc_dma_hw_params) from [<c09c143c>] (soc_pcm_hw_params+0x4b0/0x650) [ 48.105903] [<c09c143c>] (soc_pcm_hw_params) from [<c09c36a8>] (dpcm_fe_dai_hw_params+0x70/0xe4) [ 48.114715] [<c09c36a8>] (dpcm_fe_dai_hw_params) from [<c099b274>] (snd_pcm_hw_params+0x158/0x418) [ 48.123701] [<c099b274>] (snd_pcm_hw_params) from [<c099c5a0>] (snd_pcm_ioctl+0x734/0x183c) [ 48.132079] [<c099c5a0>] (snd_pcm_ioctl) from [<c029ff94>] (ksys_ioctl+0x2ac/0xb98) [ 48.139765] [<c029ff94>] (ksys_ioctl) from [<c0100080>] (ret_fast_syscall+0x0/0x28) [ 48.147440] Exception stack(0xed3c5fa8 to 0xed3c5ff0) [ 48.152515] 5fa0: bec28670 00e92870 00000004 c25c4111 bec28670 0002000f [ 48.160716] 5fc0: bec28670 00e92870 00e92820 00000036 0000bb80 00000000 0002c2f8 00000003 [ 48.168913] 5fe0: b6f4d3fc bec2853c b6ee7655 b6e22cf8 [ 48.174236] fsl-esai-dai 2024000.esai: Cannot create DMA dma:tx symlink

The dma channel is already requested by Back-End cpu dai driver, if fsl_asrc_dma requests dma chan with same dma:tx symlink, then this warning comes out.

The warning is added by commit 71723a96b8b1 ("dmaengine: Create symlinks between DMA channels and slaves") commit bad83565eafe ("dmaengine: Cleanups for the slave <-> channel symlink support")

As the dma channel is requested by Back-End, we need to reuse the channel and avoid to request a new one, then the issue can be fixed.

In order to get the dma channel which is already requested in Back-End. we export 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 --- include/sound/dmaengine_pcm.h | 11 ++++++ include/sound/soc.h | 2 ++ sound/soc/fsl/fsl_asrc_common.h | 2 ++ sound/soc/fsl/fsl_asrc_dma.c | 49 +++++++++++++++++++++------ sound/soc/soc-core.c | 3 +- sound/soc/soc-generic-dmaengine-pcm.c | 12 ------- 6 files changed, 55 insertions(+), 24 deletions(-)

diff --git a/include/sound/dmaengine_pcm.h b/include/sound/dmaengine_pcm.h index b65220685920..8c5e38180fb0 100644 --- a/include/sound/dmaengine_pcm.h +++ b/include/sound/dmaengine_pcm.h @@ -161,4 +161,15 @@ int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,

#define SND_DMAENGINE_PCM_DRV_NAME "snd_dmaengine_pcm"

+struct dmaengine_pcm { + struct dma_chan *chan[SNDRV_PCM_STREAM_LAST + 1]; + const struct snd_dmaengine_pcm_config *config; + struct snd_soc_component component; + unsigned int flags; +}; + +static inline struct dmaengine_pcm *soc_component_to_pcm(struct snd_soc_component *p) +{ + return container_of(p, struct dmaengine_pcm, component); +} #endif diff --git a/include/sound/soc.h b/include/sound/soc.h index 74868436ac79..565612a8d690 100644 --- a/include/sound/soc.h +++ b/include/sound/soc.h @@ -444,6 +444,8 @@ int devm_snd_soc_register_component(struct device *dev, const struct snd_soc_component_driver *component_driver, struct snd_soc_dai_driver *dai_drv, int num_dai); void snd_soc_unregister_component(struct device *dev); +struct snd_soc_component *snd_soc_lookup_component_nolocked(struct device *dev, + const char *driver_name); struct snd_soc_component *snd_soc_lookup_component(struct device *dev, const char *driver_name);

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..3ad862225326 100644 --- a/sound/soc/fsl/fsl_asrc_dma.c +++ b/sound/soc/fsl/fsl_asrc_dma.c @@ -135,6 +135,7 @@ static int fsl_asrc_dma_hw_params(struct snd_soc_component *component, struct snd_dmaengine_dai_dma_data *dma_params_be = NULL; struct snd_pcm_runtime *runtime = substream->runtime; struct fsl_asrc_pair *pair = runtime->private_data; + struct snd_soc_component *component_be = NULL; struct fsl_asrc *asrc = pair->asrc; struct dma_slave_config config_fe, config_be; enum asrc_pair_index index = pair->index; @@ -142,7 +143,7 @@ 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 dma_chan *tmp_chan = NULL, *tmp_chan_new = NULL; struct device *dev_be; u8 dir = tx ? OUT : IN; dma_cap_mask_t mask; @@ -160,6 +161,7 @@ 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); break; }

@@ -205,10 +207,16 @@ 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 (component_be) + tmp_chan = soc_component_to_pcm(component_be)->chan[substream->stream]; + 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 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; + if (component_be) + pair->dma_chan[dir] = soc_component_to_pcm(component_be)->chan[substream->stream];; + 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]) { @@ -273,19 +298,21 @@ 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; } diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c index b07eca2c6ccc..d4c73e86d058 100644 --- a/sound/soc/soc-core.c +++ b/sound/soc/soc-core.c @@ -310,7 +310,7 @@ struct snd_soc_component *snd_soc_rtdcom_lookup(struct snd_soc_pcm_runtime *rtd, } EXPORT_SYMBOL_GPL(snd_soc_rtdcom_lookup);

-static struct snd_soc_component +struct snd_soc_component *snd_soc_lookup_component_nolocked(struct device *dev, const char *driver_name) { struct snd_soc_component *component; @@ -329,6 +329,7 @@ static struct snd_soc_component

return found_component; } +EXPORT_SYMBOL_GPL(snd_soc_lookup_component_nolocked);

struct snd_soc_component *snd_soc_lookup_component(struct device *dev, const char *driver_name) diff --git a/sound/soc/soc-generic-dmaengine-pcm.c b/sound/soc/soc-generic-dmaengine-pcm.c index f728309a0833..80a4e71f2d95 100644 --- a/sound/soc/soc-generic-dmaengine-pcm.c +++ b/sound/soc/soc-generic-dmaengine-pcm.c @@ -21,18 +21,6 @@ */ #define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(31)

-struct dmaengine_pcm { - struct dma_chan *chan[SNDRV_PCM_STREAM_LAST + 1]; - const struct snd_dmaengine_pcm_config *config; - struct snd_soc_component component; - unsigned int flags; -}; - -static struct dmaengine_pcm *soc_component_to_pcm(struct snd_soc_component *p) -{ - return container_of(p, struct dmaengine_pcm, component); -} - static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm, struct snd_pcm_substream *substream) {