Based on Kernel commit 240181fd0ffa6 from Brian Norris: The MTD API reports -EUCLEAN only if the maximum number of bitflips found in any ECC block exceeds a certain threshold. This is done to avoid excessive -EUCLEAN reports to MTD users, which may induce additional scrubbing of data, even when the ECC algorithm in use is perfectly capable of handling the bitflips. This threshold can be controlled by user-space (via sysfs), to allow users to determine what they are willing to tolerate in their application. But it still helps to have sane defaults. In recent discussion [1], it was pointed out that our default threshold is equal to the correction strength. That means that we won't actually report any -EUCLEAN (i.e., "bitflips were corrected") errors until there are almost too many to handle. It was determined that 3/4 of the correction strength is probably a better default. [1] http://lists.infradead.org/pipermail/linux-mtd/2015-January/057259.html Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> --- drivers/mtd/nand/nand_base.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index 554d3d2..ec5a8b7 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -3718,7 +3718,7 @@ int nand_scan_tail(struct mtd_info *mtd) * properly set. */ if (!mtd->bitflip_threshold) - mtd->bitflip_threshold = mtd->ecc_strength; + mtd->bitflip_threshold = DIV_ROUND_UP(mtd->ecc_strength * 3, 4); /* Check, if we should skip the bad block table scan */ if (chip->options & NAND_SKIP_BBTSCAN) -- 2.7.0 _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
