We have a problem about the EMMC Write Protection for specific segments。
We coded the program according to the JESD84-B45（emmc 4.5）.This process is shown in the following diagram.But we found that the return value of the CMD31(SEND_WR_PROTECT_TYPE) was always not correct, and after executing this code，we could still write this block, so we thought the block was unlocked. And we found that the register was set correctly（US_PERM_WP_DIS and US_PWR_WP_EN）, and the CMD28(SET_WR_PROT) was transferred correctly whose response was also OK.
So would you know the reason why we were failed？Or can you offer us some suggests or some code examples?
Thanks very much!.