Re: [PATCH v2 3/3] arm64: dts: exynos: Add SPI nodes for Exynos850

From: Tudor Ambarus <tudor.ambarus@linaro.org>
To: Sam Protsenko <semen.protsenko@linaro.org>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Rob Herring <robh+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Alim Akhtar <alim.akhtar@samsung.com>,
	Sylwester Nawrocki <s.nawrocki@samsung.com>,
	Tomasz Figa <tomasz.figa@gmail.com>,
	Chanwoo Choi <cw00.choi@samsung.com>,
	linux-samsung-soc@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2 3/3] arm64: dts: exynos: Add SPI nodes for Exynos850
Date: Tue, 30 Jan 2024 06:11:05 +0000	[thread overview]
Message-ID: <c9b01ae6-cc3f-4447-9b5a-261d234bc92a@linaro.org> (raw)
In-Reply-To: <CAPLW+4ntySsQVA5u4TNWuc0KCbhQY61XcsBqC=O8GRoXmS_NYA@mail.gmail.com>

On 1/29/24 19:39, Sam Protsenko wrote:
>>> +                             samsung,spi-src-clk = <0>;
>> this optional property
>>
> The reason this property is provided here despite being optional, is
> to avoid corresponding dev_warn() message from spi-s3c64xx.c driver:
> 
>         if (of_property_read_u32(dev->of_node, "samsung,spi-src-clk", &temp)) {
>             dev_warn(dev, "spi bus clock parent not specified, using
> clock at index 0 as parent\n");
> 
> The same usage (samsung,spi-src-clk = <0>) can be encountered in
> multiple other Exynos dts in arch/arm/ and arch/arm64/, and it's also
> used in bindings example. Probably for the same reason explained
> above. Even if dev_warn() is removed in the driver, I guess the older
> kernels will still print it if spi-src-clk is omitted. So I'd like to
> keep it here.

Yeah, I know. I proposed a patch switching to dev_dbg. If it's so
annoying and implies adding superfluous properties to DT, maybe it is
worth to add a fixes tag to the dev_dbg patch and backport it to stable
kernels?

Your patch looks fine. I guess the vendor specific properties shall be
last if you keep them, see:
https://www.kernel.org/doc/html/latest/devicetree/bindings/dts-coding-style.html#order-of-properties-in-device-node

If you remove the vendor properties or reorder them, one can add:
Reviewed-by: Tudor Ambarus <tudor.ambarus@linaro.org>