Re: [PATCH 3/3] sound: ASoC: tegra: Select tegra30 i2s and ahub for tegra124 SoC

[Stephen Warren]

On 04/18/2017 10:38 AM, Paul Kocialkowski wrote:
> Le mardi 18 avril 2017 Ã 10:15 -0600, Stephen Warren a Ãcrit :
> > On 04/18/2017 09:11 AM, Paul Kocialkowski wrote:
> > > This selects the tegra30 i2s and ahub controllers for the tegra124 SoC.
> > > These are needed when building without ARCH_TEGRA_3x_SOC set.
> > > diff --git a/sound/soc/tegra/Kconfig b/sound/soc/tegra/Kconfig
> > > index efbe8d4c019e..bcd18d2cf7a7 100644
> > > --- a/sound/soc/tegra/Kconfig
> > > +++ b/sound/soc/tegra/Kconfig
> > > @@ -46,7 +46,7 @@ config SND_SOC_TEGRA20_SPDIF
> > >
> > >  config SND_SOC_TEGRA30_AHUB
> > >  	tristate
> > > -	depends on SND_SOC_TEGRA && ARCH_TEGRA_3x_SOC
> > > +	depends on SND_SOC_TEGRA && (ARCH_TEGRA_3x_SOC ||
> > > ARCH_TEGRA_124_SOC)
> >
> > Is this really a compile-time dependency?
>
> From a quick look at the code, I doubt this is really a build dependency.
>
> > If so, don't we need to add T210 and T186 entries into that || condition too,
> > since we could be building a kernel with just T210/T186 support and no T124
> > support?
>
> In the spirit of this patch, adding entries for other tegra platforms would make
> sense. Would you prefer that we leave out the dependency from SND_SOC_TEGRA30_*
> and only select the right I2S driver to use in each codec driver?
>
> If not, we'd have to list all relevant platforms both in the I2S/AHUB drivers
> and in each codec's rules (which is not necessarily and issue, but there's no
> need to have artificial platform dependencies).
>
> What do you think?

I think we should just remove most of these "depends on" since they're 
mostly set up to reflect runtime requirements rather than build time 
requirements. The only points I'd make are:

1)

Everything should "depends on SND_SOC_TEGRA" simply so the options don't 
show up and clutter menuconfig menus unless SND_SOC_TEGRA is enabled.

2)

SND_SOC_TEGRA30_I2S does need the Tegra30 AHUB driver in order to 
compile/link, since it directly calls functions in that driver. This is 
already handled by SND_SOC_TEGRA30_I2S doing "select SND_SOC_TEGRA30_AHUB".

3)

The machine drivers all do e.g. "select SND_SOC_TEGRA30_I2S if 
ARCH_TEGRA_3x_SOC". This was an attempt to make the machine drivers only 
pull in the relevant drivers for the SoC(s) being compiled for. I'm not 
sure this still makes sense; this won't work on kernels that only 
support T124/T210/T186 since ARCH_TEGRA_3x_SOC isn't enabled then. 
Should we just remove all those and make sure the defconfigs are updated 
to make sure the relevant I2S/AHUB/SPDIF/AC97 drivers are explicitly 
enabled? Perhaps we should default all the I2S/AHUB/SPDIF/AC97 to y 
(which will only apply if SND_SOC_TEGRA is enabled)?