+#define CFG_LINUX_COMPATIBLE_ECC
- */
It seems odd that backwards compatibility requires turning *off* an option with "compatible" in the name... I'd invert the sense of the ifdef, and have it be something like CFG_BROKEN_ECC_COMPATIBILITY.
The concern with this is people that use their own custom config files will need to add this #define when they upgrade. How about just changing the name to CFG_NEW_NAND_ECC_FORMAT then?
I like CFG_NEW_NAND_ECC_FORMAT better as well.
#if defined(CFG_NAND_LARGEPAGE) && !defined(CFG_LINUX_COMPATIBLE_ECC) /* Comment this #error out only if you really really have to. */ #error "You are using old ECC code that is broken on large page devices. See doc/README.davinci" #endif
This forces the user to make a choice - they'll probably curse while they're doing it, but they can't plead ignorance when they find their large page NAND isn't detecting ECC errors.
I like this too. Maybe a #warning for small pages as well. Of course both would also depend on #ifdef CFG_NAND_HW_ECC.
Perhaps we could use some currently unused OOB byte as a marker for new/old ECC layout?
Could do, but any filesystems which use the OOB bytes might step on these. It also complicates the code even moreso and creates a lot more scenarios to test and that could go wrong.
I really do believe it should be a clean switch from one format to the other, for both small and large page NAND, with no run-time backwards compatibility. But that's just my POV.
I hope that eventually we can remove the old format, but this patch has my ack.
Thanks Bernard
Troy