Re: [PATCH v5 3/4] ASoC: Intel - add makefile support for SKL driver

[Takashi Iwai <tiwai@suse.de>]

At Mon, 15 Jun 2015 16:57:52 +0100,
Mark Brown wrote:
> 
> On Thu, Jun 11, 2015 at 10:03:57PM +0530, Vinod Koul wrote:
> 
> > +config SND_SKL_PREALLOC_SIZE
> > +	int "Pre-allocated buffer size for skylake HD-audio driver"
> > +	range 0 32768
> > +	default 64
> 
> Size in units of...?
> 
> > +	help
> > +	  Specifies the default pre-allocated buffer-size in kB for the
> > +	  HD-audio driver.  A larger buffer (e.g. 2048) is preferred
> > +	  for systems using PulseAudio.  The default 64 is chosen just
> > +	  for compatibility reasons.
> 
> What are those compatibility reasons - why should users have to worry
> about this?

... if a user wants to reduce the memory foot print.
2MB buffers for each stream are significant size, supposing that it
can have 16 streams.

> Should this be a module parameter or something?

The buffers can be reallocated dynamically via procfs in general, but
it's not practical and intuitive.  That's why the similar option was
provided for HDA legacy driver.  It was the time when PA started
accepted slowly.  I don't know whether it makes sense for SKL ASoC
driver, though -- it's up to you guys.


Takashi