From: Sascha Hauer Date: Tue, 5 Dec 2017 10:51:40 +0000 (+0100) Subject: mtd: nand: gpmi: Fix failure when a erased page has a bitflip at BBM X-Git-Tag: microblaze-4.16-rc1~113^2~4 X-Git-Url: http://git.monstr.eu/?a=commitdiff_plain;h=fdf2e821052958a114618a95ab18a300d0b080cb;p=linux-2.6-microblaze.git mtd: nand: gpmi: Fix failure when a erased page has a bitflip at BBM When erased subpages are read then the BCH decoder returns STATUS_ERASED if they are all empty, or STATUS_UNCORRECTABLE if there are bitflips. When there are bitflips, we have to set these bits again to show the upper layers a completely erased page. When a bitflip happens in the exact byte where the bad block marker is, then this byte is swapped with another byte in block_mark_swapping(). The correction code then detects a bitflip in another subpage and no longer corrects the bitflip where it really happens. Correct this behaviour by calling block_mark_swapping() after the bitflips have been corrected. In our case UBIFS failed with this bug because it expects erased pages to be really empty: UBIFS error (pid 187): ubifs_scan: corrupt empty space at LEB 36:118735 UBIFS error (pid 187): ubifs_scanned_corruption: corruption at LEB 36:118735 UBIFS error (pid 187): ubifs_scanned_corruption: first 8192 bytes from LEB 36:118735 UBIFS error (pid 187): ubifs_scan: LEB 36 scanning failed UBIFS error (pid 187): do_commit: commit failed, error -117 Signed-off-by: Sascha Hauer Reviewed-by: Richard Weinberger Acked-by: Boris Brezillon Signed-off-by: Richard Weinberger --- diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c index 50f8d4a1b983..d4d824ef64e9 100644 --- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c +++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c @@ -1067,9 +1067,6 @@ static int gpmi_ecc_read_page(struct mtd_info *mtd, struct nand_chip *chip, return ret; } - /* handle the block mark swapping */ - block_mark_swapping(this, payload_virt, auxiliary_virt); - /* Loop over status bytes, accumulating ECC status. */ status = auxiliary_virt + nfc_geo->auxiliary_status_offset; @@ -1158,6 +1155,9 @@ static int gpmi_ecc_read_page(struct mtd_info *mtd, struct nand_chip *chip, max_bitflips = max_t(unsigned int, max_bitflips, *status); } + /* handle the block mark swapping */ + block_mark_swapping(this, buf, auxiliary_virt); + if (oob_required) { /* * It's time to deliver the OOB bytes. See gpmi_ecc_read_oob()