u-boot flash probing not working(sf probe 0)

问题

I am trying to replace flash memory blocks however, i could not probe any flash:

device>sf probe 0
SF: Unsupported flash IDs: manuf ff, jedec ffff, ext_jedec ffff
Failed to initialize SPI flash at 0:0

Do you know how to handle this or any possible reasons or workaround?

Thanks.

来源：https://stackoverflow.com/questions/46585542/u-boot-flash-probing-not-workingsf-probe-0