Re: [PATCH v2 13/13] ARM: s3c24xx: camif: include header with prototypes and unify declaration

From: Sylwester Nawrocki <s.nawrocki@samsung.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: 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>,
	Krzysztof Kozlowski <krzk@kernel.org>,
	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 15:11:41 +0200	[thread overview]
Message-ID: <6ccf14a9-802f-25b8-494d-e957cafd073d@samsung.com> (raw)
In-Reply-To: <CAK8P3a1xXe56k5nKuCJ-25h1VqWKRb9JGnFrr=SPg_icay-vZA@mail.gmail.com>

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:
>>>
>>> It seems there have never been any callers and the entire file
>>> can just be removed, with the rest of that platform_data header
>>> file moved to drivers/media/platform/s3c-camif/.
>>
>> Yes, it seems that patch never made it to mainline:
>> https://protect2.fireeye.com/v1/url?k=abe5f73a-f6293cfe-abe47c75-0cc47a314e9a-7fafe832d055d852&q=1&e=2596ffb6-c4cb-492a-8c6f-a0e261567842&u=https%3A%2F%2Fgit.linuxtv.org%2Fsnawrocki%2Fmedia.git%2Fcommit%2F%3Fh%3Dtesting%2Fs3c-camif%26id%3D355cbf835aff2aabf78390931cbbaa608af77967
> 
> I suppose it would still apply if anyone was interested, but I see your
> point.
> 
>> I doubt there are still users of camera on the s3c2440 boards
>> with current mainline kernels, if any at all, there are much
>> better HW alternatives right now.
> 
> 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.

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.

-- 
Regards,
Sylwester