On Sun, Feb 07, 2021 at 06:23:50PM +0800, Shengjiu Wang wrote: > +static int fsl_rpmsg_hw_params(struct snd_pcm_substream *substream, > + struct snd_pcm_hw_params *params, > + struct snd_soc_dai *dai) > +{ ... > + ret = clk_prepare_enable(rpmsg->mclk); > + if (ret) > + dev_err(dai->dev, "failed to enable mclk: %d\n", ret); > + > + return ret; > +} > + > +static int fsl_rpmsg_hw_free(struct snd_pcm_substream *substream, > + struct snd_soc_dai *dai) > +{ > + struct fsl_rpmsg *rpmsg = snd_soc_dai_get_drvdata(dai); > + > + clk_disable_unprepare(rpmsg->mclk); hw_params() can be called multiple times and there's no need for it to be balanced with hw_free(), I'd move this to a different callback (DAPM should work well).