On 02/12/15 21:08, Jonas Gorski wrote: > On Wed, Dec 2, 2015 at 9:54 PM, Brian Norris > <computersforpe...@gmail.com> wrote: >> >> BTW, I think Kamal had code to handle protecting bitflips in erased >> pages code in the Broadcom STB Linux BSP. Perhaps he can port that to >> upstream with nand_check_erased_ecc_chunk()? IIUC, that would probably >> handle your case too, Simon, although it wouldn't be optimal for an >> all-0xff check (i.e., bitflip_threshold == 0). >> >> If that's really an issue (i.e., we have an implementation + data), I'm >> sure we could add optimization to nand_check_erased_ecc_chunk() to >> support the bitflip_threshold == 0 case. > > Maybe I'm missing something, but wasn't the point of introducing > nand_check_erased_ecc_chunk that bitflips in erased pages should be > treated as bitflips corrected by the ecc, and therefore fixed up > before passing the data further on? So having a theshold of 0 would be > wrong / no protection at all, and could be quite destructive on MLC > nand, where bitflips in erased pages are rather common.
Without this patch I can't access erased pages at all. I don't know if the controller will still return an uncorrectable error if the page is erased but has 1 or more bit flips. -- Simon Arlott -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
