Re: [PATCH v3] ASoC: atmel: ATMEL drivers don't need HAS_DMA

From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Randy Dunlap <rdunlap@infradead.org>
Cc: Codrin.Ciubotariu@microchip.com,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	ALSA Development Mailing List <alsa-devel@alsa-project.org>,
	Liam Girdwood <lgirdwood@gmail.com>,
	Mark Brown <broonie@kernel.org>,
	mirq-linux@rere.qmqm.pl,
	Alexandre Belloni <alexandre.belloni@free-electrons.com>
Subject: Re: [PATCH v3] ASoC: atmel: ATMEL drivers don't need HAS_DMA
Date: Thu, 2 Sep 2021 18:44:23 +0200	[thread overview]
Message-ID: <CAMuHMdU=ODKZJ0OOsuCeJnTWuM3fP5DE7coSzB=fvAbxPQWDcg@mail.gmail.com> (raw)
In-Reply-To: <49495ab9-5039-f332-2895-1a79c034f58d@infradead.org>

Hi Randy,

On Thu, Jul 8, 2021 at 6:51 PM Randy Dunlap <rdunlap@infradead.org> wrote:
> On 7/8/21 1:19 AM, Codrin.Ciubotariu@microchip.com wrote:
> > On 08.07.2021 00:47, Randy Dunlap wrote:
> >> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> >>
> >> On a config (such as arch/sh/) which does not set HAS_DMA when MMU
> >> is not set, several ATMEL ASoC drivers select symbols that cause
> >> kconfig warnings. There is one "depends on HAS_DMA" which is no longer
> >> needed. Dropping it eliminates the kconfig warnings and still builds
> >> with no problems reported.
> >>
> >> Fix the following kconfig warnings:
> >>
> >> WARNING: unmet direct dependencies detected for SND_ATMEL_SOC_PDC
> >>    Depends on [n]: SOUND [=m] && !UML && SND [=m] && SND_SOC [=m] && SND_ATMEL_SOC [=m] && HAS_DMA [=n]
> >>    Selected by [m]:
> >>    - SND_ATMEL_SOC_SSC [=m] && SOUND [=m] && !UML && SND [=m] && SND_SOC [=m] && SND_ATMEL_SOC [=m]
> >>    - SND_ATMEL_SOC_SSC_PDC [=m] && SOUND [=m] && !UML && SND [=m] && SND_SOC [=m] && SND_ATMEL_SOC [=m] && ATMEL_SSC [=m]
> >>
> >> WARNING: unmet direct dependencies detected for SND_ATMEL_SOC_SSC_PDC
> >>    Depends on [n]: SOUND [=m] && !UML && SND [=m] && SND_SOC [=m] && SND_ATMEL_SOC [=m] && ATMEL_SSC [=m] && HAS_DMA [=n]
> >>    Selected by [m]:
> >>    - SND_AT91_SOC_SAM9G20_WM8731 [=m] && SOUND [=m] && !UML && SND [=m] && SND_SOC [=m] && SND_ATMEL_SOC [=m] && (ARCH_AT91 || COMPILE_TEST [=y]) && ATMEL_SSC [=m] && SND_SOC_I2C_AND_SPI [=m]
> >>
> >> WARNING: unmet direct dependencies detected for SND_ATMEL_SOC_SSC
> >>    Depends on [n]: SOUND [=m] && !UML && SND [=m] && SND_SOC [=m] && SND_ATMEL_SOC [=m] && HAS_DMA [=n]
> >>    Selected by [m]:
> >>    - SND_ATMEL_SOC_SSC_DMA [=m] && SOUND [=m] && !UML && SND [=m] && SND_SOC [=m] && SND_ATMEL_SOC [=m] && ATMEL_SSC [=m]
> >>
> >> WARNING: unmet direct dependencies detected for SND_ATMEL_SOC_SSC_DMA
> >>    Depends on [n]: SOUND [=m] && !UML && SND [=m] && SND_SOC [=m] && SND_ATMEL_SOC [=m] && ATMEL_SSC [=m] && HAS_DMA [=n]
> >>    Selected by [m]:
> >>    - SND_ATMEL_SOC_WM8904 [=m] && SOUND [=m] && !UML && SND [=m] && SND_SOC [=m] && SND_ATMEL_SOC [=m] && (ARCH_AT91 || COMPILE_TEST [=y]) && ATMEL_SSC [=m] && I2C [=m]
> >>    - SND_AT91_SOC_SAM9X5_WM8731 [=m] && SOUND [=m] && !UML && SND [=m] && SND_SOC [=m] && SND_ATMEL_SOC [=m] && (ARCH_AT91 || COMPILE_TEST [=y]) && ATMEL_SSC [=m] && SND_SOC_I2C_AND_SPI [=m]
> >>
> >> Fixes: 3951e4aae2ce ("ASoC: atmel-pcm: dma support based on pcm dmaengine")
> >> Fixes: 18291410557f ("ASoC: atmel: enable SOC_SSC_PDC and SOC_SSC_DMA in Kconfig")
> >> Fixes: 061981ff8cc8 ("ASoC: atmel: properly select dma driver state")
> >
> > I am not sure about these fixes tags. As Alexandre mentioned, it looks
> > like the reason for HAS_DMA in the first place was the COMPILE_TEST with
> > m32r arch. I dig a bit, and, if any, I think we should use:
> > Fixes: eb17726b00b3 ("m32r: add simple dma")
> > since this commit adds dummy DMA support for m32r and seems to fix the
> > HAS_DMA dependency.
>
> Ah, I forgot to update the Fixes: tag(s).
>
> I won't disagree with your Fixes: suggestion (good digging) but
> I would probably have used 8d7d11005e930:
>   ASoC: atmel: fix build failure
> which is the commit that added "depends on HAS_DMA".

M32r was not the only platform NO_DMA, so I guess the build would
have failed for the others, too (e.g. Sun-3).

So the real fix was probably commit f29ab49b5388b2f8 ("dma-mapping:
Convert NO_DMA get_dma_ops() into a real dummy"), or one of the
related commits adding dummies to subsystems.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds