linux-kernel - Re: [PATCH 08/29] media: mfc: Add Exynos‑MFC driver probe support

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Message-ID: <75d06769-4896-4095-9969-03a517705196@samsung.com>
Date: Tue, 30 Sep 2025 17:46:09 +0200
From: Marek Szyprowski <m.szyprowski@...sung.com>
To: Krzysztof Kozlowski <krzk@...nel.org>, Himanshu Dewangan
	<h.dewangan@...sung.com>
Cc: mchehab@...nel.org, robh@...nel.org, krzk+dt@...nel.org,
	conor+dt@...nel.org, sumit.semwal@...aro.org, christian.koenig@....com,
	alim.akhtar@...sung.com, manjun@...sung.com, nagaraju.s@...sung.com,
	ih0206.lee@...sung.com, jehyung.lee@...sung.com,
	linux-arm-kernel@...ts.infradead.org, linux-media@...r.kernel.org,
	devicetree@...r.kernel.org, linux-samsung-soc@...r.kernel.org,
	linux-kernel@...r.kernel.org, dri-devel@...ts.freedesktop.org,
	linaro-mm-sig@...ts.linaro.org
Subject: Re: [PATCH 08/29] media: mfc: Add Exynos‑MFC driver probe support

Hi Krzysztof,

On 30.09.2025 07:54, Krzysztof Kozlowski wrote:
> On Tue, 30 Sept 2025 at 12:56, Himanshu Dewangan <h.dewangan@...sung.com> wrote:
>> From: Nagaraju Siddineni <nagaraju.s@...sung.com>
>>
>> Introduce a new Kconfig entry VIDEO_EXYNOS_MFC for the Samsung
>> Exynos MFC driver that supports firmware version 13 and later.
>> Extend the top‑level Samsung platform Kconfig to disable the legacy
>> S5P‑MFC driver when its firmware version is > v12 and to select the
>> new Exynos‑MFC driver only when VIDEO_SAMSUNG_S5P_MFC is not enabled.
>>
>> Add exynos-mfc Kconfig and Makefile for probe functionality and creation
>> of decoder and encoder device files by registering the driver object
>> exynos_mfc.o and other relevant source files.
>>
>> Provide header files mfc_core_ops.h and mfc_rm.h containing core
>>    operation prototypes, resource‑manager helpers,
>>    and core‑selection utilities.
>>
>> Add a configurable option MFC_USE_COREDUMP to enable core‑dump
>> support for debugging MFC errors.
>>
>> These changes bring support for newer Exynos‑based MFC hardware,
>> cleanly separate it from the legacy S5P‑MFC driver, and lay the
>> groundwork for future feature development and debugging.
>>
> No, NAK. Existing driver is well tested and already used on newest
> Exynos SoC, so all this new driver is exactly how you should not work
> in upstream. You need to integrate into existing driver.
>
> Samsung received this review multiple times already.

Please don't be so categorical. The MFC hardware evolved quite a bit 
from the ancient times of S5PV210 SoC, when s5p-mfc driver was designed. 
The feature list of the new hardware hardly matches those and I really 
don't see the reason for forcing support for so different hardware in a 
single driver. Sometimes it is easier just to have 2 separate drivers if 
the common part is just the acronym in the hardware block name...

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland