Hi Pierre, On Mon, Jun 08, 2020 at 02:44:12PM -0500, Pierre-Louis Bossart wrote: > Recent changes in the ASoC core prevent multi-cpu BE dailinks from > being used. DPCM does support multi-cpu DAIs for BE Dailinks, but not > for FE. First I want to apologize for introducing this regression. Actually when I made the "Only allow playback/capture if supported" patch I did not realize it would also be used for BE DAIs. :) > > Handle the FE checks first, and make sure all DAIs support the same > capabilities within the same dailink. > > BugLink: https://github.com/thesofproject/linux/issues/2031 > Fixes: 9b5db059366ae2 ("ASoC: soc-pcm: dpcm: Only allow playback/capture if supported") > Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx> > Reviewed-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx> > Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@xxxxxxxxxxxxxxx> > Reviewed-by: Ranjani Sridharan <ranjani.sridharan@xxxxxxxxxxxxxxx> > Reviewed-by: Daniel Baluta <daniel.baluta@xxxxxxxxx> > --- > sound/soc/soc-pcm.c | 44 ++++++++++++++++++++++++++++++++++---------- > 1 file changed, 34 insertions(+), 10 deletions(-) > > diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c > index 276505fb9d50..2c114b4542ce 100644 > --- a/sound/soc/soc-pcm.c > +++ b/sound/soc/soc-pcm.c > @@ -2789,20 +2789,44 @@ int soc_new_pcm(struct snd_soc_pcm_runtime *rtd, int num) > struct snd_pcm *pcm; > char new_name[64]; > int ret = 0, playback = 0, capture = 0; > + int stream; > int i; > > + if (rtd->dai_link->dynamic && rtd->num_cpus > 1) { > + dev_err(rtd->dev, > + "DPCM doesn't support Multi CPU for Front-Ends yet\n"); > + return -EINVAL; > + } > + > if (rtd->dai_link->dynamic || rtd->dai_link->no_pcm) { > - cpu_dai = asoc_rtd_to_cpu(rtd, 0); > - if (rtd->num_cpus > 1) { > - dev_err(rtd->dev, > - "DPCM doesn't support Multi CPU yet\n"); > - return -EINVAL; > + if (rtd->dai_link->dpcm_playback) { > + stream = SNDRV_PCM_STREAM_PLAYBACK; > + > + for_each_rtd_cpu_dais(rtd, i, cpu_dai) > + if (!snd_soc_dai_stream_valid(cpu_dai, > + stream)) { > + dev_err(rtd->card->dev, > + "CPU DAI %s for rtd %s does not support playback\n", > + cpu_dai->name, > + rtd->dai_link->stream_name); > + return -EINVAL; Unfortunately the "return -EINVAL" here and below break the case where dpcm_playback/dpcm_capture does not exactly match the capabilities of the referenced CPU DAIs. To quote from my commit message: At the moment, PCM devices for DPCM are only created based on the dpcm_playback/capture parameters of the DAI link, without considering if the CPU/FE DAI is actually capable of playback/capture. Normally the dpcm_playback/capture parameter should match the capabilities of the CPU DAI. However, there is no way to set that parameter from the device tree (e.g. with simple-audio-card or qcom sound cards). dpcm_playback/capture are always both set to 1. The basic idea for my commit was to basically stop using dpcm_playback/capture for the device tree case and infer the capabilities solely based on referenced DAIs. The DAIs expose if they are capable of playback/capture, so I see no reason to be required to duplicate that into the DAI link setup (unless you want to specifically restrict a DAI link to one direction for some reason...) With your patch probe now fails with: 7702000.sound: CPU DAI MultiMedia1 for rtd MultiMedia1 does not support capture because sound/soc/qcom/common.c sets dpcm_playback = dpcm_capture = 1 even though that FE DAI is currently configured to be playback-only. I believe Srinivas fixed that problem for the BE DAIs in commit a2120089251f ("ASoC: qcom: common: set correct directions for dailinks") (https://lore.kernel.org/alsa-devel/20200612123711.29130-2-srinivas.kandagatla@xxxxxxxxxx/) For the QCOM case it may be feasible to set dpcm_playback/dpcm_capture appropriately because it is basically only used with one particular DAI driver. But simple-audio-card is generic and used with many different drivers so hard-coding a call into some other driver like Srinivas did above won't work in that case. I wonder if we should downgrade your dev_err(...) to a dev_dbg(...), and then simply avoid setting playback/capture = 0. This should fix the case I'm talking about. What do you think? Thanks, Stephan > + } > + playback = 1; > + } > + if (rtd->dai_link->dpcm_capture) { > + stream = SNDRV_PCM_STREAM_CAPTURE; > + > + for_each_rtd_cpu_dais(rtd, i, cpu_dai) > + if (!snd_soc_dai_stream_valid(cpu_dai, > + stream)) { > + dev_err(rtd->card->dev, > + "CPU DAI %s for rtd %s does not support capture\n", > + cpu_dai->name, > + rtd->dai_link->stream_name); > + return -EINVAL; > + } > + capture = 1; > } > - > - playback = rtd->dai_link->dpcm_playback && > - snd_soc_dai_stream_valid(cpu_dai, SNDRV_PCM_STREAM_PLAYBACK); > - capture = rtd->dai_link->dpcm_capture && > - snd_soc_dai_stream_valid(cpu_dai, SNDRV_PCM_STREAM_CAPTURE); > } else { > /* Adapt stream for codec2codec links */ > int cpu_capture = rtd->dai_link->params ? > -- > 2.20.1 >
