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Subject: Re: [PATCH 3/4] arm64: dts: exynos: Align DMA controller bus node
 name with dtschema
To:     Krzysztof Kozlowski <krzk@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Kukjin Kim <kgene@kernel.org>, devicetree@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
        Sylwester Nawrocki <snawrocki@kernel.org>,
        Alim Akhtar <alim.akhtar@samsung.com>,
        Chanwoo Choi <cw00.choi@samsung.com>,
        Pankaj Dubey <pankaj.dubey@samsung.com>
From:   Marek Szyprowski <m.szyprowski@samsung.com>
Message-ID: <3c1eb3fe-8eef-1f91-ff4e-3081a871fc80@samsung.com>
Date:   Tue, 30 Jun 2020 09:34:52 +0200
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Hi Krzysztof,

On 29.06.2020 22:44, Krzysztof Kozlowski wrote:
> AMBA is a bus so name the node with DMA controllers just as "bus" to fix
> dtschema warnings like:
>
>      amba: $nodename:0: 'amba' does not match '^(bus|soc|axi|ahb|apb)(@[0-9a-f]+)?$'
>
> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

Do we really need a separate 'bus' for those DMA controllers?

IMHO they are not different from the hw perspective from the other 
devices available on the SoC. A separate bus is a historical thing, they 
work fine when moved directly under the 'soc' node. The separate bus 
only mimics the way Linux organizes its drivers. This comment affects 
both ARM and ARM64.

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