Re: [GIT PULL] sound updates for 4.15-rc1

[Pierre-Louis Bossart]

On 11/15/17 1:34 AM, Takashi Iwai wrote:
> [Adding more people and alsa-devel to Cc]
>
> On Wed, 15 Nov 2017 03:40:09 +0100,
> Linus Torvalds wrote:
> > On Tue, Nov 14, 2017 at 6:51 AM, Takashi Iwai <tiwai@xxxxxxx> wrote:
> > > please pull sound updates for v4.15-rc1 from:
> >
> > Hmm. Making "oldconfig" on my laptop with this, my
> > SND_SOC_INTEL_SKYLAKE went away.
> >
> > And the reason seems to be that new SND_SOC_INTEL_SST_TOPLEVEL config option.
> >
> > Which has no help associated with it.
> >
> > This is not a friendly thing to do to people. It basically breaks
> > existing setups for no documented reason, and with no explanation.
> >
> > Please fix the config situation. At the very least, add documentation.
>
> Sorry about that.  I saw Vinod already submitted a patch to add the
> help text to CONFIG_SND_SOC_INTEL_SST_TOPLEVEL, so the least fix
> should go in soon.
>
> But now looking at these changes, I noticed a few things, too:
>
> - With the introduction of SND_SOC_INTEL_SST_TOPLEVEL, keeping
>    SND_SOC_INTEL_COMMON and SND_SOC_INTEL_MACH individually doesn't
>    make much sense.  They can be dropped and replaced with
>    SND_SOC_INTEL_SST_TOPLEVEL as a further cleanup.
>
> - ... or, make SND_SOC_INTEL_SST_TOPLEVEL=y as default, if this is
>    considered to be a top-level filter config (like the network vendor
>    kconfig items).  In that case, the reverse-selection of
>    SND_SOC_INTEL_COMMON and SND_SOC_INTEL_MACH should be avoided, but
>    they should be selected from the actual drivers instead.

This level was introduced as a shortcut to help select the platform 
drivers associated with the closed-source audio firmware.
There will be a follow-up set of patches coming soon, and we'll need to 
have the corresponding top-level selector for the drivers handling the 
open-source audio firmware. Please don't make too many assumptions on 
this SND_SOC_INTEL_SST_TOPLEVEL, it is not going to be true for everyone 
moving forward.

If you want look at the Kconfig setup, the latest code cherry-picked on 
top of v4.14 is here
https://github.com/plbossart/sound/tree/backport/intel-audio-stable-v4.14

the menuconfig options are still in device drivers/sound/ASoC but now 
you have SST and SOF menus.

> And I believe there are a few more possible cleanups / fixes in the
> messy Intel ASoC Kconfigs.  For example, SND_SOC_INTEL_SST is almost
> always set.  The only exception is via SND_SST_ATOM_HIFI2_PLATFORM.
> But all machine drivers using Atom Hifi2 do set SND_SST_IPC_ACPI,
> which also requires SND_SOC_INTEL_SST.
>
> Further looking at this, we see that the only entry that does *not*
> require SND_SOC_INTEL_SST is the case with SND_MFLD_MACHINE in
> sound/soc/intel/boards.  And now more interesting part -- there is no
> corresponding entry in Makefile.  That is, this kconfig is effectively
> dead!  The source code mfld_machine.c exists, but it's just a place
> holder now.  The code was supposed to be integrated into atom
> directory by the commit b97169da0699, but it seems forgotten to be
> updated.
>
> Hmm...
>
>
> Takashi