Re: [PATCH] ASoC: SOF: sort out Kconfig, again

From: Arnd Bergmann <arnd@arndb.de>
To: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Cc: Liam Girdwood <lgirdwood@gmail.com>,
	Stephen Rothwell <sfr@canb.auug.org.au>,
	Mark Brown <broonie@kernel.org>,
	Daniel Baluta <daniel.baluta@nxp.com>,
	Ranjani Sridharan <ranjani.sridharan@linux.intel.com>,
	Kai Vehmanen <kai.vehmanen@linux.intel.com>,
	Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>,
	Shawn Guo <shawnguo@kernel.org>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	Fabio Estevam <festevam@gmail.com>,
	NXP Linux Team <linux-imx@nxp.com>,
	YueHaibing <yuehaibing@huawei.com>,
	Krzysztof Kozlowski <krzk@kernel.org>,
	sound-open-firmware@alsa-project.org,
	ALSA Development Mailing List <alsa-devel@alsa-project.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] ASoC: SOF: sort out Kconfig, again
Date: Wed, 29 Apr 2020 00:01:39 +0200	[thread overview]
Message-ID: <CAK8P3a24whg2RhJE3Vf5u3EWy+wvFqhXdp7EQZuQx0shPsMARw@mail.gmail.com> (raw)
In-Reply-To: <6b39fbba-c65d-2c02-14bf-11c2d00547af@linux.intel.com>

On Tue, Apr 28, 2020 at 11:43 PM Pierre-Louis Bossart
<pierre-louis.bossart@linux.intel.com> wrote:
> On 4/28/20 4:27 PM, Arnd Bergmann wrote:
> > The imx8 config keeps causing issues:
> >
> > WARNING: unmet direct dependencies detected for SND_SOC_SOF_IMX8M
> >    Depends on [n]: SOUND [=y] && !UML && SND [=y] && SND_SOC [=m] && SND_SOC_SOF_TOPLEVEL [=y] && SND_SOC_SOF_IMX_TOPLEVEL [=y] && IMX_DSP [=n]
> >    Selected by [m]:
> >    - SND_SOC_SOF_IMX_OF [=m] && SOUND [=y] && !UML && SND [=y] && SND_SOC [=m] && SND_SOC_SOF_TOPLEVEL [=y] && SND_SOC_SOF_IMX_TOPLEVEL [=y] && SND_SOC_SOF_IMX8M_SUPPORT [=y]
> >
> > This is complicated by two drivers having dependencies on both
> > platform specific drivers and the SND_SOC_SOF_OF framework code,
> > and using an somewhat obscure method to build them the same way
> > as the SOC_SOF_OF symbol (built-in or modular).
> >
> > My solution now ensures that the two drivers can only be enabled
> > when the dependencies are met:
> >
> > - When the platform specific drivers are built-in, everything is
> >    fine, as SOC_SOF_OF is either =y or =m
> >
> > - When both are loadable modules, it also works, both for Kconfig
> >    and at runtime
> >
> > - When the hardware drivers are loadable modules or disabled, and
> >    SOC_SOF_OF=y, prevent the IMX_SOF_OF drivers from being turned on,
> >    as this would be broken.
> >
> > It seems that this is just an elaborate way to describe two tristate
> > symbols that have straight dependencies, but maybe I'm missing some
> > subtle point. It seems to always build for me now.
>
> Thanks Arnd, do you mind sharing your config?

https://pastebin.com/HRX5xi3R

> We noticed last week that
> there's a depend/select confusion might be simpler to fix, see
> https://github.com/thesofproject/linux/pull/2047/commits
>
> If I look at the first line I see a IMX_DSP=n which looks exactly like
> what we wanted to fix.

Yes, I think that fix addresses the build warning as well, but looking
more closely I don't think it's what you want: If you do this on
a config that has the IMX_DSP disabled, it would appear to the
user that you have enabled the drivers, but the actual code is still
disabled.

      Arnd