@@ -3484,6 +3484,13 @@ int nand_scan_tail(struct mtd_info *mtd)
/* propagate ecc info to mtd_info */
mtd->ecclayout = chip->ecc.layout;
mtd->ecc_strength = chip->ecc.strength;
+ /*
+ * Initialize bitflip_threshold to its default prior scan_bbt() call.
+ * scan_bbt() might invoke mtd_read(), thus bitflip_threshold must be
+ * properly set.
+ */
+ if (!mtd->bitflip_threshold)
+ mtd->bitflip_threshold = mtd->ecc_strength;
/* Check, if we should skip the bad block table scan */
if (chip->options & NAND_SKIP_BBTSCAN)
As of edbc454 [mtd: driver _read() returns max_bitflips; mtd_read() returns -EUCLEAN], 'mtd->bitflip_threshold' must be set for mtd devices having ECC, prior any 'mtd_read()' call. Otherwise, 'mtd_read()' will falsely return -EUCLEAN. Normally, 'mtd->bitflip_threshold' is initialized when the MTD is added. However, this is too late for NAND MTDs, as 'scan_bbt()' is invoked prior the existing initialization of 'mtd->bitflip_threshold'. This is a problem since 'scan_bbt()' calls 'mtd_read()', in the case of a flash-based bad block table. It resulted in a falsely reported bitflips indication during BBT read, which lead to constant scrubbing of the flash BBT blocks. Initialize 'mtd->bitflip_threshold' to its default value (if not already set by the driver), prior invocation of 'scan_bbt()'. Reported-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com> --- - The issue was introduced in v3.5-rc1, and needs to be merged prior v3.5 - Sascha, I've credited you as reporter, is that ok with you? - Sashca, care to test the fix on your system?