On Monday 27 April 2009, Scott Wood wrote:
It is for compatibility with a widely-deployed legacy ECC layout -- more details can be found in the list archives.
See my original query, which IMO disproves that assertion.
What this option enables differs in two ways from what the MontaVista code does. (Speaking here of the 1-bit HW ECC. The 4-bit support is another mess, which would be made far worse by needing to carry the BROKEN_ECC mode.)
One could define a MONTAVISTA_COMPAT option, but it would not AFAICT be this BROKEN_ECC since it would only differ from the current Linux code in *one* of those three ways. (Which has in turn also been claimed to be broken, by mis-reporting some multi-bit errors as single-bit ones.)
Which is why I'm wondering what that original U-Boot code for HW ECC was trying to be "compatible" with, since it clearly wasn't MontaVista Linux ... or even the U-Boot versions I've seen be distributed with it.
- Dave