From: Haibo Chen haibo.chen@nxp.com For FSL_USDHC, it do not implement VENDORSPEC_CKEN/PEREN/HCKEN/IPGEN, these are reserved bits. Instead, use VENDORSPEC_FRC_SDCLK_ON to gate on/off the card clock output. After commit b5874b552ffa ("mmc: fsl_esdhc_imx: add wait_dat0() support"), we meet SD3.0 card can't work at UHS mode, mmc_switch_voltage() fail because the second mmc_wait_dat0 return -ETIMEDOUT. According to SD spec, during voltage switch, need to gate off/on the card clock. If not set the FRC_SDCLK_ON, after CMD11, hardware will gate off the card clock automatically, so card do not detect the clock off/on behavior, so will draw the data0 line low until next command. Fixes: b5874b552ffa ("mmc: fsl_esdhc_imx: add wait_dat0() support") Tested-by: Tim Harvey tharvey@gateworks.com Signed-off-by: Haibo Chen haibo.chen@nxp.com
Applied to u-boot-imx, master, thanks !
Best regards, Stefano Babic