[alsa-devel] [EXT] Re: [PATCH 1/3] ASoC: fsl_asrc: Use in(out)put_format instead of in(out)put_word_width

[Nicolin Chen]

On Tue, Sep 10, 2019 at 02:22:06AM +0000, S.j. Wang wrote:
> Hi
> 
> > 
> > On Mon, Sep 09, 2019 at 06:33:19PM -0400, Shengjiu Wang wrote:
> > > snd_pcm_format_t is more formal than enum asrc_word_width, which
> > has
> > > two property, width and physical width, which is more accurate than
> > > enum asrc_word_width. So it is better to use in(out)put_format instead
> > > of in(out)put_word_width.
> > 
> > Hmm...I don't really see the benefit of using snd_pcm_format_t here...I
> > mean, I know it's a generic one, and would understand if we use it as a
> > param for a common API. But this patch merely packs the "width" by
> > intentionally using this snd_pcm_format_t and then adds another
> > translation to unpack it.. I feel it's a bit overcomplicated. Or am I missing
> > something?
> > 
> > And I feel it's not necessary to use ALSA common format in our own "struct
> > asrc_config" since it is more IP/register specific.
> > 
> > Thanks
> > Nicolin
> > 
> 
> As you know, we have another M2M function internally, when user want to
> Set the format through M2M API, it is better to use snd_pcm_format_t instead the
> Width, for snd_pcm_format_t include two property, data with and physical width
> In driver some place need data width, some place need physical width.
> For example how to distinguish S24_LE and S24_3LE in driver,  DMA setting needs
> The physical width,  but ASRC need data width. 
> 
> Another purpose is that we have another new designed ASRC, which support more
> Formats, I would like it can share same API with this ASRC, using snd_pcm_format_t
> That we can use the common API, like snd_pcm_format_linear,
> snd_pcm_format_big_endian to get the property of the format, which is needed by
> driver.

I see. Just acked the patch.