External emmc on nano SDMMC3

Autonomous Machines Jetson & Embedded Systems Jetson Nano
1

Hi, I’m working on our custom board using NANO emmc module.
And we need more storge space so we insert a external emmc on our board which is connected to SDMMC3.

For our other custom board using Xavier NX, the external emmc can work fine just to enable the SDMMC3 device tree node like this

    sdhci@3440000 {
        status = "okay";
        non-removable;
        no-sdio;
        no-sd;
    };

We can see nano’s pin is just the same as xavier nx, so I did the same in our nano board dt file

	sdhci@700b0400 {
        status = "okay";
        non-removable;
        no-sdio;
        no-sd;
	};

But after flash, it seems our board can not detect our external emmc as mmcblk1, there is only mmcblk0(the module emmc)

I find the same question in these topic

It seems the sdmmc3 device tree node in nano is different from Xavier NX’s and need to configure it to support emmc. And from this topic, it seems he can use the external emmc on sdmmc3.

Is there any help to do it?
How can I change the device tree node

2

I did the same thing in

			override@1 {
				target = <&sdhci2>;
				_overlay_ {
					vqmmc-supply = <&max77620_ldo6>;
					no-sdio;
					no-sd;
					//no-mmc;
					//sd-uhs-sdr104;
					//sd-uhs-sdr50;
					//sd-uhs-sdr25;
					//sd-uhs-sdr12;
				};

And I can detect the emmc on SDMMC3, and I can format、mount、write/read it normally.
But there is error ouput in dmesg just as same as the topic said, it seems not affect the usage?
I wonder is this a stable way to use external emmc?

3

We do not support external eMMC design, not able to provide further comments, sorry for that.

4

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