From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mms2.broadcom.com ([216.31.210.18]) by canuck.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1R1OZz-0001gT-0J for linux-mtd@lists.infradead.org; Wed, 07 Sep 2011 20:18:39 +0000 From: "Brian Norris" To: "Artem Bityutskiy" Subject: [PATCH 10/14] mtd: nand: scrub BBT on ECC errors Date: Wed, 7 Sep 2011 13:13:37 -0700 Message-ID: <1315426421-16243-11-git-send-email-computersforpeace@gmail.com> In-Reply-To: <1315426421-16243-1-git-send-email-computersforpeace@gmail.com> References: <1315426421-16243-1-git-send-email-computersforpeace@gmail.com> MIME-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Kevin Cernekee , Matthieu Castet , Jim Quinlan , linux-mtd@lists.infradead.org, Brian Norris , David Woodhouse , Matthew Creech List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Now that `read_bbt()' returns ECC error codes properly, we handle those codes when checking the integrity of our flash-based BBT. The modifications can be described by this new policy: *) On any uncorrected ECC error, we invalidate the corresponding table and retry our version-checking integrity logic. *) On corrected ECC errors, we mark both tables for re-writing to flash (a.k.a. scrubbing). Current integrity checks (i.e., comparing version numbers, etc.) should take care of all the cases that result in rescanning the device for bad blocks or falling back to the BBT as found in the mirror descriptor. Signed-off-by: Brian Norris --- drivers/mtd/nand/nand_bbt.c | 29 ++++++++++++++++++++++++----- 1 files changed, 24 insertions(+), 5 deletions(-) diff --git a/drivers/mtd/nand/nand_bbt.c b/drivers/mtd/nand/nand_bbt.c index 37df614..cc24119 100644 --- a/drivers/mtd/nand/nand_bbt.c +++ b/drivers/mtd/nand/nand_bbt.c @@ -882,7 +882,7 @@ static inline int nand_memory_bbt(struct mtd_info *mtd, struct nand_bbt_descr *b */ static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd) { - int i, chips, writeops, create, chipsel, res; + int i, chips, writeops, create, chipsel, res, res2; struct nand_chip *this = mtd->priv; struct nand_bbt_descr *td = this->bbt_td; struct nand_bbt_descr *md = this->bbt_md; @@ -899,6 +899,7 @@ static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_desc create = 0; rd = NULL; rd2 = NULL; + res = res2 = 0; /* Per chip or per device? */ chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1; /* Mirrored table available? */ @@ -951,11 +952,29 @@ static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_desc } /* Read back first? */ - if (rd) - read_abs_bbt(mtd, buf, rd, chipsel); + if (rd) { + res = read_abs_bbt(mtd, buf, rd, chipsel); + if (is_uncorrected_ecc_error(res)) { + /* Mark table as invalid */ + rd->pages[i] = -1; + i--; + continue; + } + } /* If they weren't versioned, read both */ - if (rd2) - read_abs_bbt(mtd, buf, rd2, chipsel); + if (rd2) { + res2 = read_abs_bbt(mtd, buf, rd2, chipsel); + if (is_uncorrected_ecc_error(res2)) { + /* Mark table as invalid */ + rd2->pages[i] = -1; + i--; + continue; + } + } + + /* Scrub the flash table(s)? */ + if (is_corrected_ecc_error(res) || is_corrected_ecc_error(res2)) + writeops = 0x03; /* Write the bad block table to the device? */ if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) { -- 1.7.5.4