[PATCH 9/9] ASoC: SOF: ipc4-pcm: add delay function support

[Jaroslav Kysela]

On 01. 02. 23 13:32, Peter Ujfalusi wrote:

> +static snd_pcm_sframes_t sof_ipc4_pcm_delay(struct snd_soc_component *component,
> +					    struct snd_pcm_substream *substream)
> +{

...

> +
> +	/*
> +	 * Handle 32-bit counter wrap around, which would happen
> +	 * for a 48khz 2ch stream in 24.855 hours
> +	 */
> +	link_ptr = tmp_ptr & UINT_MAX;
> +
> +	host_ptr = substream->runtime->status->hw_ptr;
> +
> +	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
> +		return host_ptr - link_ptr;
> +
> +	return link_ptr - host_ptr;

I don't think that this calculation is fine for the wrap point. The hw_ptr is 
in range 0..pcm_boundary not UINT_MAX. Also, you should consider the 
underrun/overrun situations. The simple substraction is not enough to handle 
this correctly.

						Jaroslav

-- 
Jaroslav Kysela <perex at perex.cz>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.