> +static int acp5x_dma_open(struct snd_soc_component *component,
> + struct snd_pcm_substream *substream)
> +{
> + struct snd_pcm_runtime *runtime;
> + struct snd_soc_pcm_runtime *prtd;
> + struct i2s_dev_data *adata;
> + struct i2s_stream_instance *i2s_data;
> + int ret;
> +
> + runtime = substream->runtime;
> + prtd = asoc_substream_to_rtd(substream);
> + component = snd_soc_rtdcom_lookup(prtd, DRV_NAME);
> + adata = dev_get_drvdata(component->dev);
> +
> + i2s_data = kzalloc(sizeof(*i2s_data), GFP_KERNEL);
> + if (!i2s_data)
> + return -EINVAL;
return -ENOMEM?
> +
> + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
> + runtime->hw = acp5x_pcm_hardware_playback;
> + else
> + runtime->hw = acp5x_pcm_hardware_capture;
> +
> + ret = snd_pcm_hw_constraint_integer(runtime,
> + SNDRV_PCM_HW_PARAM_PERIODS);
> + if (ret < 0) {
> + dev_err(component->dev, "set integer constraint failed\n");
> + kfree(i2s_data);
> + return ret;
> + }
> + i2s_data->acp5x_base = adata->acp5x_base;
> + runtime->private_data = i2s_data;
> + return ret;
> +}
> +
> +static int acp5x_dma_hw_params(struct snd_soc_component *component,
> + struct snd_pcm_substream *substream,
> + struct snd_pcm_hw_params *params)
> +{
> + struct i2s_stream_instance *rtd;
> + struct snd_soc_pcm_runtime *prtd;
> + struct snd_soc_card *card;
> + struct acp5x_platform_info *pinfo;
> + struct i2s_dev_data *adata;
> + u64 size;
> +
> + prtd = asoc_substream_to_rtd(substream);
> + card = prtd->card;
> + pinfo = snd_soc_card_get_drvdata(card);
> + adata = dev_get_drvdata(component->dev);
> + rtd = substream->runtime->private_data;
> +
> + if (!rtd)
> + return -EINVAL;
> +
> + if (pinfo) {
> + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
> + rtd->i2s_instance = pinfo->play_i2s_instance;
> + switch (rtd->i2s_instance) {
> + case I2S_HS_INSTANCE:
> + adata->play_stream = substream;
> + break;
> + case I2S_SP_INSTANCE:
> + default:
> + adata->i2ssp_play_stream = substream;
> + }
> + } else {
> + rtd->i2s_instance = pinfo->cap_i2s_instance;
> + switch (rtd->i2s_instance) {
> + case I2S_HS_INSTANCE:
> + adata->capture_stream = substream;
> + break;
> + case I2S_SP_INSTANCE:
> + default:
> + adata->i2ssp_capture_stream = substream;
> + }
> + }
> + } else {
> + dev_err(component->dev, "pinfo failed\n");
should you bail here with e.g. return -EINVAL?
> + }
> + size = params_buffer_bytes(params);
> + rtd->dma_addr = substream->dma_buffer.addr;
> + rtd->num_pages = (PAGE_ALIGN(size) >> PAGE_SHIFT);
> + config_acp5x_dma(rtd, substream->stream);
> + return 0;
> +}
