Hello,

On 04/06/2019 06:37:48+0000, Jurgen Lambrecht wrote:

Hi,

When following https://bootlin.com/blog/eight-channels-audio-on-i-mx7-with-pcm3168/ I get this error (from soc_core.c):

... kernel: [    3.059634][   T15] pcm3168a 3-0039: ASoC: Failed to set DAI format: -22

I could propose this patch (I get that printf when applying the patch) (all other errors in that file have a printf):

diff --git a/sound/soc/codecs/pcm3168a.c b/sound/soc/codecs/pcm3168a.c index 08d3fe192e65..75ccbb919902 100644 --- a/sound/soc/codecs/pcm3168a.c +++ b/sound/soc/codecs/pcm3168a.c @@ -353,6 +353,7 @@ static int pcm3168a_set_dai_fmt(struct snd_soc_dai *dai,         case SND_SOC_DAIFMT_NB_NF:                 break;         default: +               dev_err(component->dev, "wrong INV_MASK\n");                 return -EINVAL;         }

But why does this code returns an error for code that has no effect? OK, it could be because SND_SOC_DAIFMT_INV_MASK must be SND_SOC_DAIFMT_NB_NF. But then Alexandre's blog contains an error, because the dac TDM sets frame-inversion in its dts (and it should not).

While I'm pretty sure what is in the blog is working (it is deployed in production), I remember there was something fishy with frame-inversion. I unfortunately don't remember the specifics.

Honestly, I would think you can remove frame-inversion safely as the codec is only supposed to support NB_NF.