On 1/12/23 00:58, Chancel Liu wrote: > The commit 1da681e52853 ("ASoC: soc-pcm.c: Clear DAIs parameters after > stream_active is updated") tries to make sure DAIs parameters can be > cleared properly through moving the cleanup to the place where > stream_active is updated. However, it will cause the cleanup only > happening in soc_pcm_close(). > > Suppose a case: aplay -Dhw:0 44100.wav 48000.wav. The case calls > soc_pcm_open()->soc_pcm_hw_params()->soc_pcm_hw_free()-> > soc_pcm_hw_params()->soc_pcm_hw_free()->soc_pcm_close() in order. The > parameters would be remained in the system even if the playback of > 44100.wav is finished. > > The case requires us clearing parameters in phase of soc_pcm_hw_free(). > We shouldn't use stream_active to decide if we must do the cleanup > since it is finally updated in soc_pcm_close(). > > This patch introduces a usage count called hw_params_count in > snd_soc_dai structure. It records the times of setting parameters to > this DAI then decreases each time soc_pcm_hw_free() is called. If the > count decreases to 0, it means this DAI is not used now and we should > clear the parameters. what makes you think that the use of hw_params and hw_free is symmetrical? A couple of years ago we found a case where the FE hw_params failed, and in that case the BE hw_free was called without the BE hw_params ever being invoked first. This is due to the DPCM error handling, and as a result all our hw_free implementations test if the resources are actually allocated/valid and never assume hw_params was used. IIRC it's also valid to call hw_params multiple times without calling hw_free every time. > Fixes: 1da681e52853 ("ASoC: soc-pcm.c: Clear DAIs parameters after stream_active is updated") > > Signed-off-by: Chancel Liu <chancel.liu@xxxxxxx> > --- > include/sound/soc-dai.h | 3 +++ > sound/soc/soc-pcm.c | 16 +++++++++++----- > 2 files changed, 14 insertions(+), 5 deletions(-) > > diff --git a/include/sound/soc-dai.h b/include/sound/soc-dai.h > index ea7509672086..a7e589a0fe72 100644 > --- a/include/sound/soc-dai.h > +++ b/include/sound/soc-dai.h > @@ -451,6 +451,9 @@ struct snd_soc_dai { > unsigned int channels; > unsigned int sample_bits; > > + /* Count of setting DAI parameters */ > + unsigned int hw_params_count; > + > /* parent platform/codec */ > struct snd_soc_component *component; > > diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c > index 579a44d81d9a..2c2a5dcf9e06 100644 > --- a/sound/soc/soc-pcm.c > +++ b/sound/soc/soc-pcm.c > @@ -711,14 +711,10 @@ static int soc_pcm_clean(struct snd_soc_pcm_runtime *rtd, > > if (!rollback) { > snd_soc_runtime_deactivate(rtd, substream->stream); > - /* clear the corresponding DAIs parameters when going to be inactive */ > - for_each_rtd_dais(rtd, i, dai) { > - if (snd_soc_dai_active(dai) == 0) > - soc_pcm_set_dai_params(dai, NULL); > > + for_each_rtd_dais(rtd, i, dai) > if (snd_soc_dai_stream_active(dai, substream->stream) == 0) > snd_soc_dai_digital_mute(dai, 1, substream->stream); > - } > } > > for_each_rtd_dais(rtd, i, dai) > @@ -949,6 +945,14 @@ static int soc_pcm_hw_clean(struct snd_soc_pcm_runtime *rtd, > > snd_soc_dpcm_mutex_assert_held(rtd); > > + /* clear the corresponding DAIs parameters when hw_params_count decreases to 0 */ > + for_each_rtd_dais(rtd, i, dai) > + if (snd_soc_dai_stream_valid(dai, substream->stream)) { > + dai->hw_params_count--; > + if (dai->hw_params_count == 0) > + soc_pcm_set_dai_params(dai, NULL); > + } > + > /* run the stream event */ > snd_soc_dapm_stream_stop(rtd, substream->stream); > > @@ -1051,6 +1055,7 @@ static int __soc_pcm_hw_params(struct snd_soc_pcm_runtime *rtd, > > soc_pcm_set_dai_params(codec_dai, &codec_params); > snd_soc_dapm_update_dai(substream, &codec_params, codec_dai); > + codec_dai->hw_params_count++; > } > > for_each_rtd_cpu_dais(rtd, i, cpu_dai) { > @@ -1068,6 +1073,7 @@ static int __soc_pcm_hw_params(struct snd_soc_pcm_runtime *rtd, > /* store the parameters for each DAI */ > soc_pcm_set_dai_params(cpu_dai, params); > snd_soc_dapm_update_dai(substream, params, cpu_dai); > + cpu_dai->hw_params_count++; > } > > ret = snd_soc_pcm_component_hw_params(substream, params);