Tuning failed, falling back to fixed sampling clock
https://www.xilinx.com/support/answers/73079.html
2019.2 Zynq UltraScale+ MPSoC: PetaLinux ZCU106 BSP fails to detect SD Card FAT32 or EXT4 partition when booting Linux
Solution
This is a known issue in the 2019.2 ZCU106 BSP.
To fix this issue, you will need add device-tree node property to <plnx-proj-root>/project-spec/meta-user/recipes-bsp/device-tree/files/system-user.dtsi
1) Modify the system-user.dtsi file with below content:
$ vim <plnx-proj-root>/project-spec/meta-user/recipes-bsp/device-tree/files/system-user.dtsi
# system-user.dtsi content
"/include/ "system-conf.dtsi"
/ {
};
&sdhci1 {
no-1-8-v;
};
"/include/ "system-conf.dtsi"
/ {
};
&sdhci1 {
no-1-8-v;
};
2) Clean the device-tree sstate cache and rebuild the device-tree:
$ petalinux-build -c device-tree -x cleansstate
$ petalinux-build -c device-tree
Note: This solution also applies to the 2019.2 ZCU106 VCU TRD PetaLinux BSP.