Hi Andrea, Adding Han in Cc.
On Fri, 31 Jul 2015 12:07:21 +0200 Andrea Scian <[email protected]> wrote: > > Dear Boris, > > > Il 30/07/2015 19:34, Boris Brezillon ha scritto: > > The default NAND read functions are relying on an underlying controller > > to correct bitflips, but some of those controller cannot properly fix > > bitflips in erased pages. > > In case of ECC failures, check if the page of subpage is empty before > > reporting an ECC failure. > > I'm still wondering if chip->ecc.strength is the right threshold. > > Did you see my comments here [1]? WDYT? Yes I've read it, and decided to go for ecc->strength as a first step (I'm more interested in discussing the approach than the threshold value right now ;-)). Anyway, as you pointed out in the thread, writing data on an erased page already containing some bitflips might generate even more bitflips, so using a different threshold for the erased page check makes sense. This threshold should definitely be correlated to the ECC strength, but how, that's the question. How about taking a rather conservative value like 10% of the specified ECC strength, and see how it goes. > > Maybe we can have this discussion in a separate thread, if you want ;-) No, I think we should keep discussing it in this thread. Thanks, Boris -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
