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Subject: Re: [PATCH v3] ASoC: atmel: ATMEL drivers don't need HAS_DMA
To:     Geert Uytterhoeven <geert@linux-m68k.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>
References: <20210707214752.3831-1-rdunlap@infradead.org>
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 <a94c9788-0415-ffe3-9dd4-e6ed8d7ee96a@infradead.org>
 <CAMuHMdWUcaC-xiW0UiVdTpx-R=e_i8eHSNc8JF_wqbcO6FynWw@mail.gmail.com>
 <f5cf4155-785f-9ec7-1f59-be5c92911b0a@infradead.org>
 <CAMuHMdXcmW27KhQEgxmVSDgR8GDnb_5mYNPYepa15F_tKqk9-A@mail.gmail.com>
From:   Randy Dunlap <rdunlap@infradead.org>
Message-ID: <9c1bbf15-ebba-e754-8fac-9cc7b218651c@infradead.org>
Date:   Thu, 9 Sep 2021 18:53:03 -0700
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On 9/9/21 12:22 AM, Geert Uytterhoeven wrote:
> Hi Randy,
> 
> On Wed, Sep 8, 2021 at 10:14 PM Randy Dunlap <rdunlap@infradead.org> wrote:
>> On 9/6/21 12:14 AM, Geert Uytterhoeven wrote:
>>> On Fri, Sep 3, 2021 at 9:53 PM Randy Dunlap <rdunlap@infradead.org> wrote:
>>>> On 9/2/21 9:44 AM, Geert Uytterhoeven wrote:
>>>>> 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.
>>>>
>>>> Does this mean that some other actions are needed here?
>>>> E.g. revert + a different kind of fix?
>>>
>>> While we can now compile drivers using DMA features on NO_DMA
>>> platforms, thanks to the dummies, it does mean many of these drivers
>>> cannot work on such platforms.  So I think it makes sense to replace
>>> "depends on HAS_DMA" by "depends on HAS_DMA || COMPILE_TEST" if DMA
>>> is not optional to the driver.
>>
>> Hi Geert,
>>
>> Is this what you had in mind?  It seems to work with my (limited)
>> testing.
> 
> Yes. And also for other symbols for drivers that now compile fine
> if !HAS_DMA, thanks to the dummies.
> 
>> --- linux-next-20210907.orig/sound/soc/atmel/Kconfig
>> +++ linux-next-20210907/sound/soc/atmel/Kconfig
>> @@ -11,6 +11,7 @@ if SND_ATMEL_SOC
>>
>>    config SND_ATMEL_SOC_PDC
>>          bool
>> +       depends on HAS_DMA || COMPILE_TEST
>>
>>    config SND_ATMEL_SOC_DMA
>>          bool

Well. Addressing only sound/, only one more patch is needed AFAICT.
For Kconfigs outside of sound/, that would be more of a medium-length
project.


Lightly/successfully build-tested.

---
  sound/soc/fsl/Kconfig |    2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

--- linux-next-20210907.orig/sound/soc/fsl/Kconfig
+++ linux-next-20210907/sound/soc/fsl/Kconfig
@@ -5,7 +5,7 @@ comment "Common SoC Audio options for Fr
  
  config SND_SOC_FSL_ASRC
  	tristate "Asynchronous Sample Rate Converter (ASRC) module support"
-	depends on HAS_DMA
+	depends on HAS_DMA || COMPILE_TEST
  	select REGMAP_MMIO
  	select SND_SOC_GENERIC_DMAENGINE_PCM
  	help