[alsa-devel] [EXT] Re: [PATCH] ASoC: fsl_asrc: replace the process_option table with function

[S.j. Wang]

> -----Original Message-----
> From: Nicolin Chen <nicoleotsuka at gmail.com>
> Sent: Wednesday, April 10, 2019 4:01 PM
> To: S.j. Wang <shengjiu.wang at nxp.com>
> Cc: timur at kernel.org; Xiubo.Lee at gmail.com; festevam at gmail.com;
> broonie at kernel.org; alsa-devel at alsa-project.org; linuxppc-
> dev at lists.ozlabs.org
> Subject: Re: [EXT] Re: [PATCH] ASoC: fsl_asrc: replace the process_option
> table with function
> 
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> 
> On Wed, Apr 10, 2019 at 07:22:31AM +0000, S.j. Wang wrote:
> > > The table was copied directly from the Reference Manual. We also
> > > have listed all supported input and output sample rates just right behind
> that table.
> > > If there're missing rates, we probably should update those two lists also?
> > > Otherwise, how could we have a driver limiting both I/O sample rates
> > > while we still see something not in the table?
> > >
> >
> > Yes,  I plan to send another patch to update the in/out rate list.  Do
> > I need To merge that to this commit?  Actually we want to support 12k
> > and 24KHz
> 
> Please send separate patches but in one series. And a question:
> 
> Is it possible to update the table? It'd be way quicker to use lookup table
> than real-time calculation all the time. I believe you can simply calculate all
> the values out for 12KHz and 24KHz since you have the function. If there are
> certain combinations of these two not being supported, then we could mark
> it with a special value and add an if-check to error out.
> 

Yes,  but I think the function should be more flexible, if someday we need to support
Other sample rate, only need to update the list.

> > > > +static int proc_autosel(int Fsin, int Fsout, int *pre_proc, int
> > > > +*post_proc)
> > >
> > > Please add some comments to this function to explain what it does,
> > > and how it works. And better to rename it to something like
> "fsl_asrc_sel_proc".
> > >
> > Yes, some comments should be added, but not so detail, because this
> > function
> 
> As much comments as possible.
> 
> > Is get from the design team, but the owner has left.
> 
> OK...that's sad...
> 
> > > Another thing confuses me: so we could have supported sample rates
> > > in the list but the hardware might not support some of them because
> > > we couldn't calculate their processing options?
> >
> > No, just want to support 12k, 24KHz, or others as customer like.
> 
> I was confused because the I/O rate lists not getting updated.
> It makes sense now if you are abort to update them.