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From: Sylwester Nawrocki <s.nawrocki@samsung.com>
To: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>, Stephen Boyd <sboyd@kernel.org>,
	Alexandre Torgue <alexandre.torgue@st.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Chanwoo Choi <cw00.choi@samsung.com>,
	Guenter Roeck <linux@roeck-us.net>, Kukjin Kim <kgene@kernel.org>,
	Kyungmin Park <kyungmin.park@samsung.com>,
	Maxime Coquelin <mcoquelin.stm32@gmail.com>,
	Michael Turquette <mturquette@baylibre.com>,
	Russell King <linux@armlinux.org.uk>,
	Simtec Linux Team <linux@simtec.co.uk>,
	Tomasz Figa <tomasz.figa@gmail.com>,
	Will Deacon <will@kernel.org>,
	Wim Van Sebroeck <wim@linux-watchdog.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	linux-clk <linux-clk@vger.kernel.org>,
	"moderated list:ARM/SAMSUNG EXYNOS ARM ARCHITECTURES" 
	<linux-samsung-soc@vger.kernel.org>,
	linux-stm32@st-md-mailman.stormreply.com,
	LINUXWATCHDOG <linux-watchdog@vger.kernel.org>,
	patches@opensource.cirrus.com,
	Sergio Prado <sergio.prado@e-labworks.com>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	Sylwester Nawrocki <snawrocki@kernel.org>,
	Cedric Roux <sed@free.fr>, Lihua Yao <ylhuajnu@outlook.com>
Subject: Re: [PATCH v2 13/13] ARM: s3c24xx: camif: include header with prototypes and unify declaration
Date: Wed, 12 Aug 2020 17:58:52 +0200	[thread overview]
Message-ID: <828b3dd5-31f0-0414-e6ea-7629b063e8ce@samsung.com> (raw)
In-Reply-To: <20200812133109.GA15697@pi3>

On 12.08.2020 15:31, Krzysztof Kozlowski wrote:
> On Wed, Aug 12, 2020 at 03:11:41PM +0200, Sylwester Nawrocki wrote:
>> On 12.08.2020 13:28, Arnd Bergmann wrote:
>>> On Wed, Aug 12, 2020 at 12:46 PM Sylwester Nawrocki
>>> <s.nawrocki@samsung.com> wrote:
>>>> On 12.08.2020 11:14, Arnd Bergmann wrote:

>>> I see two board files (and no DT) instantiate the camif device:
>>> NexVision Nexcoder 2440 and the FriendlyARM mini2440.
>>>
>>> Can you say whether the camif on those would actually work
>>> at all without your patch? If not, we know that there are no
>>> users of that driver and could either drop it completely or move
>>> it to staging for a release or two.
>>
>> Without additional patches the camif will not work, the driver 
>> needs an instance of struct s3c_camif_plat_data which specifies
>> what image sensor is attached.
>>
>> I think we can drop the driver, together with the s3c_camif_device
>> platform device definitions. It can always be added again if anyone
>> ever needs it or converts the platform to DT.
> 
> Since the header was in /include/media I assumed there might be some
> user-space tools using it. But if it is not the case, I'll drop the code
> then.

That's a kernel internal header, only for board files, it should really 
have been added to include/linux/platform_data.
  
>> IMO all non-DT code in arch/arm/mach-s3c24xx is a candidate for
>> removal, it just adds to the maintenance effort and I seriously
>> doubt there are now any users of it.
> 
> That is quite tricky... I really do not know whether there are any real
> world users of S3C24xx and S3C64xx platforms. Evalkits are mostly not
> available for buying so I do not expect new designs. However still
> existing ones might be somewhere... Few years ago, back in Samsung, I
> mentioned removing them. That time I think Marek or you Sylwester, said
> that there are industrial applications using S3C24xx. I believe, why
> not. The trouble is - how to find such users? How to get in touch for
> testing or at least for bug reports if something is broken?

I believe if there any such applications of the S3C24XX SoCs still existing 
somewhere their long term support doesn't include updating to new kernels. 
I used to keep a running S3C2440 SoC based board just for the purpose of
testing patches touching the common code, but I stopped it, I think it is
not worth to waste time and health on it any more. For example support for 
the OSELAS.BSP-Pengutronix-Mini2440 BSP I used for tests ended 5 years ago
[1].

> Or even more important - is it worth to spend effort and time on this?
> If there is no single production system using recent Linux kernel, the
> answer should be negative...

I suspect nobody cares about that code (non-DT s3c24xx) any more for other
than sentimental reasons.

[1] https://git.pengutronix.de/cgit/OSELAS.BSP-Pengutronix-Mini2440

-- 
Regards,
Sylwester


  reply	other threads:[~2020-08-12 15:59 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-04 19:26 [PATCH v2 00/13] clk/watchdog/ARM: Cleanup of various S3C bits Krzysztof Kozlowski
2020-08-04 19:26 ` [PATCH v2 01/13] clk: samsung: s3c64xx: declare s3c64xx_clk_init() in shared header Krzysztof Kozlowski
2020-08-05  1:22   ` Chanwoo Choi
2020-08-12  7:57   ` Stephen Boyd
2020-08-04 19:26 ` [PATCH v2 02/13] clk: samsung: s3c24xx: declare s3c24xx_common_clk_init() " Krzysztof Kozlowski
2020-08-05  1:23   ` Chanwoo Choi
2020-08-12  7:57   ` Stephen Boyd
2020-08-04 19:26 ` [PATCH v2 03/13] ARM: s3c64xx: include header to fix -Wmissing-prototypes Krzysztof Kozlowski
2020-08-12  7:58   ` Stephen Boyd
2020-08-04 19:26 ` [PATCH v2 04/13] ARM: s3c: remove plat-samsung/.../samsung-time.h Krzysztof Kozlowski
2020-08-04 19:26 ` [PATCH v2 05/13] ARM: samsung: fix language typo Krzysztof Kozlowski
2020-08-12  7:59   ` Stephen Boyd
2020-08-04 19:26 ` [PATCH v2 06/13] ARM: samsung: remove HAVE_S3C2410_WATCHDOG and use direct dependencies Krzysztof Kozlowski
2020-08-17 16:57   ` Krzysztof Kozlowski
2020-08-17 17:00     ` Tomasz Figa
2020-08-17 18:02     ` Guenter Roeck
2020-08-19 18:16   ` Krzysztof Kozlowski
2020-08-04 19:26 ` [PATCH v2 07/13] ARM: s3c64xx: switch to generic watchdog driver reset Krzysztof Kozlowski
2020-08-19 18:17   ` Krzysztof Kozlowski
2020-08-04 19:26 ` [PATCH v2 08/13] ARM: s3c24xx: fix missing system reset Krzysztof Kozlowski
2020-08-19 18:18   ` Krzysztof Kozlowski
2020-08-04 19:26 ` [PATCH v2 09/13] ARM: s3c24xx: include common.h header in s3c2443.c Krzysztof Kozlowski
2020-08-04 19:26 ` [PATCH v2 10/13] ARM: s3c24xx: sdhci: include plat/sdhci.h header Krzysztof Kozlowski
2020-08-04 19:26 ` [PATCH v2 11/13] ARM: s3c24xx: ts: include platform data header Krzysztof Kozlowski
2020-08-04 19:26 ` [PATCH v2 12/13] ARM: s3c24xx: ts: document function argument Krzysztof Kozlowski
2020-08-04 19:26 ` [PATCH v2 13/13] ARM: s3c24xx: camif: include header with prototypes and unify declaration Krzysztof Kozlowski
2020-08-12  7:59   ` Stephen Boyd
2020-08-12  9:14     ` Arnd Bergmann
2020-08-12 10:46       ` Sylwester Nawrocki
2020-08-12 11:28         ` Arnd Bergmann
2020-08-12 13:11           ` Sylwester Nawrocki
2020-08-12 13:31             ` Krzysztof Kozlowski
2020-08-12 15:58               ` Sylwester Nawrocki [this message]
2020-08-12 17:13                 ` Krzysztof Kozlowski
2020-08-12 18:49                   ` Sylwester Nawrocki
2020-08-27 20:52               ` Cedric Roux
2020-09-06 15:41                 ` Krzysztof Kozlowski
     [not found] ` <BY5PR13MB30639E16691A4A601A1D7070C44B0@BY5PR13MB3063.namprd13.prod.outlook.com>
2020-08-06 12:16   ` [PATCH v2 00/13] clk/watchdog/ARM: Cleanup of various S3C bits Krzysztof Kozlowski

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