@piter75@ebin-dev Feel free to confirm the rockchip emmc phy pulldown dts indeed fixes emmc write in hs400es mode (I believe on most rk3399 boards, not only helios64). Likely on kernel up and above 6.1 (for the regulator fixes).   Thanks to @RussianNeuroMancer I found: arm64: dts: rockchip: add enable-strobe-pulldown to emmc phy on nanopi4 https://github.com/torvalds/linux/commit/463be3cb357dab7d7e4d8dcc7c15c642e10c5bef and: phy: rockchip: set pulldown for strobe li