Hello,

I am responsible for implementing yaffs in a small, bare meta OS system with a 512MB, 2K pages, 64  pages block NAND Flash.

Our Flash rom subsystem is sometimes failing reads. This is happing on blocks that are supposed to be good and contains file data! Furthermore, later reads to the same page might succeed (after a system reboot).

Of course, this is wrecking havoc on our system’s reliability.

So, a couple of questions:

• have you ever seen that in your experience?
• when this happen, I make sure that the flash driver to yaffs interface returns a YAFFS_FAIL, however, yaffs does seem to still return data to the user that called the file read, incorrectly returning known bad bytes at this point. Is this normal?
• After such a bad read, yaffs does not seem to do anything on the block like mark it as bad or something like this. Is it intended?

I am working with a checkout of yaffs which is around 6 month old (taken in june 2017) in a bare metal setup.

Thanks,

Cyrille