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Message-ID: <aa947a69-a0bf-50e6-9ff2-770f436d58e2@linaro.org>
Date:   Thu, 6 Apr 2023 18:36:53 +0200
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Subject: Re: [PATCH 2/2] ARM: dts: imx6ull-dhcor: Add Marantec maveo box
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To:     Christoph Niedermaier <cniedermaier@dh-electronics.com>,
        Marek Vasut <marex@denx.de>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>
Cc:     Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Shawn Guo <shawnguo@kernel.org>, Li Yang <leoyang.li@nxp.com>,
        Fabio Estevam <festevam@denx.de>,
        NXP Linux Team <linux-imx@nxp.com>,
        kernel <kernel@dh-electronics.com>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
References: <20230405160258.46998-1-cniedermaier@dh-electronics.com>
 <20230405160258.46998-2-cniedermaier@dh-electronics.com>
 <05fa147c-116b-59b4-d14b-760bbefd7602@denx.de>
 <e7aa3b3220e148ee96f5a1c361721845@dh-electronics.com>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
In-Reply-To: <e7aa3b3220e148ee96f5a1c361721845@dh-electronics.com>
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On 05/04/2023 20:24, Christoph Niedermaier wrote:
> From: Marek Vasut [mailto:marex@denx.de]
> Sent: Wednesday, April 5, 2023 6:25 PM
>> On 4/5/23 18:02, Christoph Niedermaier wrote:
>>
>> [...]
>>
>>> +/ {
>>> +     model = "DH electronics i.MX6ULL DHCOR on maveo box";
>>> +     compatible = "dh,imx6ull-dhcor-maveo-box", "dh,imx6ull-dhcor-som",
>>> +                  "fsl,imx6ull";
>>> +
>>> +     aliases {
>>> +             /delete-property/ mmc0; /* Avoid double definitions */
>>> +             /delete-property/ mmc1;
>>> +             mmc2 = &usdhc2; /* eMMC should be mmc2 */
>>
>> Why not mmc0 ?
>>
>> Use root=PARTUUID= when booting to avoid any dependency on
>> root=/dev/mmcblk2pN enumeration.
> 
> This is due to software interchangeability with the DHCOM
> i.MX6ULL, where the eMMC is always mmc2.

That's not the reason to have aliases. The number should match numbering
in your datasheet/schematics/user-guide, not what your software wants.

Use PARTUUID for SW dependencies.

Best regards,
Krzysztof