From 6b94f118a213583ada80bab25fedacc08562392d Mon Sep 17 00:00:00 2001 From: Peter Tyser Date: Tue, 3 Feb 2015 11:58:13 -0600 Subject: [PATCH] cmd_nand: Verify writes to NAND Previously NAND writes were only verified when CONFIG_MTD_NAND_VERIFY_WRITE was defined. On boards without this define writes could fail silently. Boards with CONFIG_MTD_NAND_VERIFY_WRITE could prematurely report failures which ECC could correct. Add a verification step after all "nand write[.x]" commands to ensure the writes were successful. The verification uses ECC for for "normal" writes, but does not for raw and yaffs writes. Some test cases which inject fake bad bits on a 2K page flash are below. Test cases with CONFIG_MTD_NAND_VERIFY_WRITE defined: Example of an ECC write which previously failed when CONFIG_MTD_NAND_VERIFY_WRITE was defined, but now succeeds because ECC is used during verification: nand erase 0 0x10000 dhcp /somefile mw.b 0x10000 0xff 0x2000 mw.b 0x10020 0xfe 1 nand write.raw 0x10000 0x800 1 mw.b 0x1000020 0x01 1 nand write 0x1000000 0x800 0x1800 Test cases without CONFIG_MTD_NAND_VERIFY_WRITE defined: Example of an ECC write which previously silently failed: nand erase 0 0x10000 dhcp /somefile mw.b 0x10000 0xff 0x2000 mw.b 0x10020 0x00 1 nand write.raw 0x10000 0x800 1 mw.b 0x1000020 0xff 1 nand write 0x1000000 0x800 0x1800 Example of a raw write which previously failed silently due to stuck data bit, but now errors out: nand erase 0 0x10000 dhcp /somefile mw.b 0x10000 0xff 0x2000 mw.b 0x10020 0xfe 1 nand write.raw 0x10000 0x800 1 mw.b 0x1000020 0x01 1 nand write.raw 0x1000000 0x800 3 Example of a raw write which previously failed silently due to stuck OOB bit, but now errors out: nand erase 0 0x10000 dhcp /somefile mw.b 0x10000 0xff 0x2000 mw.b 0x10810 0xfe 1 nand write.raw 0x10000 0x800 1 mw.b 0x1000810 0x01 1 nand write.raw 0x1000000 0x800 3 Signed-off-by: Peter Tyser Tested-by: Heiko Schocher Acked-by: Heiko Schocher --- common/cmd_nand.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/common/cmd_nand.c b/common/cmd_nand.c index 7f962dc..bada28c 100644 --- a/common/cmd_nand.c +++ b/common/cmd_nand.c @@ -419,10 +419,13 @@ static int raw_access(nand_info_t *nand, ulong addr, loff_t off, ulong count, .mode = MTD_OPS_RAW }; - if (read) + if (read) { ret = mtd_read_oob(nand, off, &ops); - else + } else { ret = mtd_write_oob(nand, off, &ops); + if (!ret) + ret = nand_verify_page_oob(nand, &ops, off); + } if (ret) { printf("%s: error at offset %llx, ret %d\n", @@ -690,7 +693,8 @@ static int do_nand(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) else ret = nand_write_skip_bad(nand, off, &rwsize, NULL, maxsize, - (u_char *)addr, 0); + (u_char *)addr, + WITH_WR_VERIFY); #ifdef CONFIG_CMD_NAND_TRIMFFS } else if (!strcmp(s, ".trimffs")) { if (read) { @@ -699,7 +703,7 @@ static int do_nand(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) } ret = nand_write_skip_bad(nand, off, &rwsize, NULL, maxsize, (u_char *)addr, - WITH_DROP_FFS); + WITH_DROP_FFS | WITH_WR_VERIFY); #endif #ifdef CONFIG_CMD_NAND_YAFFS } else if (!strcmp(s, ".yaffs")) { @@ -709,7 +713,7 @@ static int do_nand(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) } ret = nand_write_skip_bad(nand, off, &rwsize, NULL, maxsize, (u_char *)addr, - WITH_YAFFS_OOB); + WITH_YAFFS_OOB | WITH_WR_VERIFY); #endif } else if (!strcmp(s, ".oob")) { /* out-of-band data */