[alsa-devel] [PATCH v5 8/8] ASoC: Intel: Skylake: add option to control HDAudio + DSP usage

[Mark Brown]

On Tue, Jul 31, 2018 at 09:06:54AM -0700, Pierre-Louis Bossart wrote:
> On 7/31/18 3:48 AM, Takashi Iwai wrote:
> > Pierre-Louis Bossart wrote:

> > > +config SND_SOC_INTEL_SKYLAKE_FORCE_HDA_DSP
> > > +	bool "Force HDAudio Codec + DSP support"
> > > +	depends on SND_SOC_INTEL_SKYLAKE_HDA_DSP
> > > +	help
> > > +	  If you have a Intel Skylake+ platform with the DSP enabled in
> > > +	  the BIOS and an HDAudio codec, then enable this option by saying Y
> > > +	  This option will ignore information from the BIOS and force the use
> > > +	  of the HDaudio codec, if present.
> > > +	  This is a debug option not recommended for distros.

> > ... and this one is better to be a module option.
> > Distros tend to enable all possible options, and this may be set
> > unnecessarily.  If any, this kconfig should be only toggling the
> > default option value.

> Sorry, I don't get this one. this wouldn't change anything between built-in
> or module, it's just a yes/no answer to ignore ACPI stuff. the default is
> also no and there is a clear statement not to include it except for debug.
> We have a similar option for SOF to bypass all ACPI information and go
> straight to 'nocodec' mode.

Debug options like these are really a lot more useful as something
runtime selectable with something like a module parameter as Takashi
suggests - an innatentive distro maintainer could easily enable it by
mistake when going through a bunch of new options in a new kernel
release and if someone needs it for debugging purposes in a distro
context it's a real pain to have to rebuild the kernel.

It's also a bit confusing as the config text says:

> > > +	  If you have a Intel Skylake+ platform with the DSP enabled in
> > > +	  the BIOS and an HDAudio codec, then enable this option by saying Y

which sounds like people should turn it on, the bit about it being a
debug option is quite deep in the text.
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