[alsa-devel] [PATCH v3 05/14] ASoC: SOF: Add PCM operations support

[Takashi Iwai]

On Tue, 11 Dec 2018 22:23:09 +0100,
Pierre-Louis Bossart wrote:
> 
> +	/* number of pages should be rounded up */
> +	if (runtime->dma_bytes % PAGE_SIZE)
> +		pcm.params.buffer.pages = (runtime->dma_bytes / PAGE_SIZE) + 1;
> +	else
> +		pcm.params.buffer.pages = runtime->dma_bytes / PAGE_SIZE;

There is likely some nice macro for this :)

> +	/* firmware already configured host stream */
> +	ret = snd_sof_pcm_platform_hw_params(sdev,
> +					     substream,
> +					     params,
> +					     &pcm.params);
> +	dev_dbg(sdev->dev, "stream_tag %d", pcm.params.stream_tag);

This error can be ignored?

> +	/* send IPC to the DSP */
> +	ret = sof_ipc_tx_message(sdev->ipc, pcm.hdr.cmd, &pcm, sizeof(pcm),
> +				 &ipc_params_reply, sizeof(ipc_params_reply));

This error value isn't evaluated immediately but passed until the
last.  Is it intentional?

> +	/* validate offset */
> +	posn_offset = ipc_params_reply.posn_offset;
> +
> +	/* check if offset is overflow or it is not aligned */
> +	if (posn_offset > sdev->stream_box.size ||
> +	    posn_offset % sizeof(struct sof_ipc_stream_posn) != 0) {
> +		dev_err(sdev->dev, "error: got wrong posn offset 0x%x for PCM %d\n",
> +			posn_offset, ret);
> +		return ret;

Here you return an error after checking more things.

> +	}
> +	spcm->posn_offset[substream->stream] =
> +		sdev->stream_box.offset + posn_offset;
> +
> +	/* save pcm hw_params */
> +	memcpy(&spcm->params[substream->stream], params, sizeof(*params));
> +
> +	return ret;

Even here returns an error after saving as if done properly.


> +static int sof_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
> +{
....
> +	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
> +
> +		/* check if the stream hw_params needs to be restored */
> +		if (spcm->restore_stream[substream->stream]) {
> +
> +			/* restore hw_params */
> +			ret = sof_restore_hw_params(substream, spcm, sdev);

This calls the hw_params that is supposed to be non-atomic.

> +	snd_sof_pcm_platform_trigger(sdev, substream, cmd);
> +
> +	/* send IPC to the DSP */
> +	ret = sof_ipc_tx_message(sdev->ipc, stream.hdr.cmd, &stream,
> +				 sizeof(stream), &reply, sizeof(reply));
> +
> +	return ret;

... so the whole trigger action is non-atomic PCM only?


thanks,

Takashi