I don’t know. Search it by yourself. Please stop asking such question. This is just basic code tracing. If you are a engineer, then it should be easy job for you.
Share the dmesg after deleting tach_gpio and applying the built dtb to jetson nano. dmesg7.txt (83.6 KB)
The sd card is still not recognized
[1.945149] sdhci: Secure Digital Host Controller Interface driver
[ 1.945151] sdhci: Copyright(c) Pierre Ossman
[ 1.945154] sdhci-pltfm: SDHCI platform and OF driver helper
[ 1.945513] sdhci-tegra sdhci-tegra.3: Client registration for eMC Successful
[ 1.949895] sdhci-tegra sdhci-tegra.2: Got CD GPIO
[ 1.950304] sdhci-tegra sdhci-tegra.2: Client registration for eMC Successful
…
[ 1.985984] mmc0: SDHCI controller on sdhci-tegra.3 [sdhci-tegra.3] using ADMA 64-bit with 64 bit addr
[ 1.995755] tegra-asoc: sound: ADMAIF1 <-> ADMAIF1 mapping ok
[ 1.995881] tegra-asoc: sound: ADMAIF2 <-> ADMAIF2 mapping ok
[ 1.996001] tegra-asoc: sound: ADMAIF3 <-> ADMAIF3 mapping ok
[ 1.996120] tegra-asoc: sound: ADMAIF4 <-> ADMAIF4 mapping ok
[ 1.996240] tegra-asoc: sound: ADMAIF5 <-> ADMAIF5 mapping ok
[ 1.996357] tegra-asoc: sound: ADMAIF6 <-> ADMAIF6 mapping ok
[ 1.996475] tegra-asoc: sound: ADMAIF7 <-> ADMAIF7 mapping ok
[ 1.996592] tegra-asoc: sound: ADMAIF8 <-> ADMAIF8 mapping ok
[ 1.996710] tegra-asoc: sound: ADMAIF9 <-> ADMAIF9 mapping ok
[ 1.996836] tegra-asoc: sound: ADMAIF10 <-> ADMAIF10 mapping ok
[ 1.998156] mmc1: SDHCI controller on sdhci-tegra.2 [sdhci-tegra.2] using ADMA 64-bit with 64 bit addr
The left is the dts file I made, and the right is the dts file I told you to compare.
Something is different. And vmmc-always-on is not applied to the dts file you told me to compare.