On Fri, 6 Jul 2018 21:27:20 +0200 Boris Brezillon <boris.brezil...@bootlin.com> wrote:
> On Mon, 25 Jun 2018 10:44:42 +1200 > Chris Packham <chris.pack...@alliedtelesis.co.nz> wrote: > > > Hi, > > > > I'm looking at adding support for the Micron MT29F1G08ABAFAWP-ITE:F chip > > Hm, it's even worse than I thought. The model name does not include the > -ITE suffix (E means ECC can't be disabled), which means we have no way > to detect the version with forced on-die ECC. > > I see 2 solutions to this problem: > 1/ Bean provides us a solution to reliably detect when ECC can be > de-actived and when it can't > 2/ We only ever expose 64 bytes of OOB to the user and consider that > ECC can be disabled, even if it can't in reality > After reading the doc again, I forgot one thing you can try before deciding to go for option #2. 8th bit in byte 5 of READID's result encodes whether the on-die ECC state (enabled or not). I remember we had a discussion with Bean where he told us this was a runtime status reflecting the on-die ECC state, which is crazy, since READID might return different values depending on the NAND state, and most of the code in the core assumes READID provides a fixed ID that encodes the chip characteristics/capabilities, not its state. Anyway, if this bit is actually reflecting the on-die ECC state and on-die cannot be disabled on your chip, it should stay at 1 even after you have sent the SET_FEATURES(DISABLE_ECC) command. Let's hope this works as I expect, otherwise we're back to option #2 until Bean suggest something else.
