On Fri, Oct 31, 2025 at 03:59:51PM +0100, Christoph Stoidner wrote: >mmc/sd specification requires a 1 ms delay (stable supply voltage) >after vdd was enabled and before issuing first command. > >For most sdcard/soc combinations, the missing delay seems to be not a >problem because the processing time between enabling vdd and the first >command is often hundreds of microseconds or more. However, in our >specific case, some sdcards were not detected by u-boot: >* soc: NXP i.MX 93 >* sdcards: SanDisk Ultra, 64GB micro SDXC 1, > MediaRange, 8GB, SDHC >* measured time between vdd and first command: approx. 784us >* symptom: both sdcards did not respond at all to first commands, > u-boot mmc subsystem ran into timeout and stops to > initialize the cards > >Signed-off-by: Christoph Stoidner <[email protected]> >Cc: Peng Fan <[email protected]> >Cc: Jaehoon Chung <[email protected]> >---
Applied. Thanks, Peng
