From dadc17a3e34810ed411a62e6b4cafdf3e5e1d5c8 Mon Sep 17 00:00:00 2001 From: Brian Norris Date: Tue, 20 Sep 2011 18:35:57 -0700 Subject: [PATCH] mtd: nand: wait to set BBT version Because there are so many cases of checking, writing, and re-writing of the bad block table(s), we might as well wait until the we've settled on a valid, clean copy of the table. This also prevents us from falsely incrementing the table version. For example, we may have the following: Primary table, with version 0x02 Mirror table, with version 0x01 Primary table has uncorrectable ECC errors If we don't have this fix applied, then we will: Choose to read the primary table (higher version) Set mirror table version to 0x02 Read back primary table Invalidate table because of ECC errors Retry readback operation with mirror table, now version 0x02 Mirrored table reads cleanly Writeback BBT to primary table location (with "version 0x02") However, the mirrored table shouldn't have a new version number. Instead, we actually want: Choose to read the primary table (higher version) Read back primary table Invalidate table because of ECC errors Retry readback with mirror table (version 0x01) Mirrored table reads cleanly Set both tables to version 0x01 Writeback BBT to primary table location (version 0x01) Signed-off-by: Brian Norris Signed-off-by: Artem Bityutskiy --- drivers/mtd/nand/nand_bbt.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/mtd/nand/nand_bbt.c b/drivers/mtd/nand/nand_bbt.c index 11185aa..e7976c7 100644 --- a/drivers/mtd/nand/nand_bbt.c +++ b/drivers/mtd/nand/nand_bbt.c @@ -909,11 +909,9 @@ static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_desc writeops = 0x03; } else if (td->pages[i] == -1) { rd = md; - td->version[i] = md->version[i]; writeops = 0x01; } else if (md->pages[i] == -1) { rd = td; - md->version[i] = td->version[i]; writeops = 0x02; } else if (td->version[i] == md->version[i]) { rd = td; @@ -921,11 +919,9 @@ static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_desc rd2 = md; } else if (((int8_t)(td->version[i] - md->version[i])) > 0) { rd = td; - md->version[i] = td->version[i]; writeops = 0x02; } else { rd = md; - td->version[i] = md->version[i]; writeops = 0x01; } } else { @@ -957,6 +953,7 @@ static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_desc if (mtd_is_eccerr(res)) { /* Mark table as invalid */ rd->pages[i] = -1; + rd->version[i] = 0; i--; continue; } @@ -967,6 +964,7 @@ static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_desc if (mtd_is_eccerr(res2)) { /* Mark table as invalid */ rd2->pages[i] = -1; + rd2->version[i] = 0; i--; continue; } @@ -976,6 +974,12 @@ static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_desc if (mtd_is_bitflip(res) || mtd_is_bitflip(res2)) writeops = 0x03; + /* Update version numbers before writing */ + if (md) { + td->version[i] = max(td->version[i], md->version[i]); + md->version[i] = td->version[i]; + } + /* Write the bad block table to the device? */ if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) { res = write_bbt(mtd, buf, td, md, chipsel); -- 2.7.4