diff options
| -rw-r--r-- | common/cmd_nand.c | 22 | ||||
| -rw-r--r-- | doc/README.nand | 21 | ||||
| -rw-r--r-- | drivers/mtd/nand/nand_util.c | 122 | ||||
| -rw-r--r-- | include/nand.h | 1 |
4 files changed, 166 insertions, 0 deletions
diff --git a/common/cmd_nand.c b/common/cmd_nand.c index 4b16069..1568594 100644 --- a/common/cmd_nand.c +++ b/common/cmd_nand.c @@ -700,6 +700,25 @@ static int do_nand(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) return ret == 0 ? 0 : 1; } +#ifdef CONFIG_CMD_NAND_TORTURE + if (strcmp(cmd, "torture") == 0) { + if (argc < 3) + goto usage; + + if (!str2off(argv[2], &off)) { + puts("Offset is not a valid number\n"); + return 1; + } + + printf("\nNAND torture: device %d offset 0x%llx size 0x%x\n", + dev, off, nand->erasesize); + ret = nand_torture(nand, off); + printf(" %s\n", ret ? "Failed" : "Passed"); + + return ret == 0 ? 0 : 1; + } +#endif + if (strcmp(cmd, "markbad") == 0) { argc -= 2; argv += 2; @@ -810,6 +829,9 @@ static char nand_help_text[] = "nand erase.chip [clean] - erase entire chip'\n" "nand bad - show bad blocks\n" "nand dump[.oob] off - dump page\n" +#ifdef CONFIG_CMD_NAND_TORTURE + "nand torture off - torture block at offset\n" +#endif "nand scrub [-y] off size | scrub.part partition | scrub.chip\n" " really clean NAND erasing bad blocks (UNSAFE)\n" "nand markbad off [...] - mark bad block(s) at offset (UNSAFE)\n" diff --git a/doc/README.nand b/doc/README.nand index c130189..a1a511c 100644 --- a/doc/README.nand +++ b/doc/README.nand @@ -108,6 +108,9 @@ Configuration Options: CONFIG_CMD_NAND Enables NAND support and commmands. + CONFIG_CMD_NAND_TORTURE + Enables the torture command (see description of this command below). + CONFIG_MTD_NAND_ECC_JFFS2 Define this if you want the Error Correction Code information in the out-of-band data to be formatted to match the JFFS2 file system. @@ -213,6 +216,24 @@ Miscellaneous and testing commands: DANGEROUS!!! Factory set bad blocks will be lost. Use only to remove artificial bad blocks created with the "markbad" command. + "torture offset" + Torture block to determine if it is still reliable. + Enabled by the CONFIG_CMD_NAND_TORTURE configuration option. + This command returns 0 if the block is still reliable, else 1. + If the block is detected as unreliable, it is up to the user to decide to + mark this block as bad. + The analyzed block is put through 3 erase / write cycles (or less if the block + is detected as unreliable earlier). + This command can be used in scripts, e.g. together with the markbad command to + automate retries and handling of possibly newly detected bad blocks if the + nand write command fails. + It can also be used manually by users having seen some NAND errors in logs to + search the root cause of these errors. + The underlying nand_torture() function is also useful for code willing to + automate actions following a nand->write() error. This would e.g. be required + in order to program or update safely firmware to NAND, especially for the UBI + part of such firmware. + NAND locking command (for chips with active LOCKPRE pin) diff --git a/drivers/mtd/nand/nand_util.c b/drivers/mtd/nand/nand_util.c index 2855683..2ba0c5e 100644 --- a/drivers/mtd/nand/nand_util.c +++ b/drivers/mtd/nand/nand_util.c @@ -683,3 +683,125 @@ int nand_read_skip_bad(nand_info_t *nand, loff_t offset, size_t *length, return 0; } + +#ifdef CONFIG_CMD_NAND_TORTURE + +/** + * check_pattern: + * + * Check if buffer contains only a certain byte pattern. + * + * @param buf buffer to check + * @param patt the pattern to check + * @param size buffer size in bytes + * @return 1 if there are only patt bytes in buf + * 0 if something else was found + */ +static int check_pattern(const u_char *buf, u_char patt, int size) +{ + int i; + + for (i = 0; i < size; i++) + if (buf[i] != patt) + return 0; + return 1; +} + +/** + * nand_torture: + * + * Torture a block of NAND flash. + * This is useful to determine if a block that caused a write error is still + * good or should be marked as bad. + * + * @param nand NAND device + * @param offset offset in flash + * @return 0 if the block is still good + */ +int nand_torture(nand_info_t *nand, loff_t offset) +{ + u_char patterns[] = {0xa5, 0x5a, 0x00}; + struct erase_info instr = { + .mtd = nand, + .addr = offset, + .len = nand->erasesize, + }; + size_t retlen; + int err, ret = -1, i, patt_count; + u_char *buf; + + if ((offset & (nand->erasesize - 1)) != 0) { + puts("Attempt to torture a block at a non block-aligned offset\n"); + return -EINVAL; + } + + if (offset + nand->erasesize > nand->size) { + puts("Attempt to torture a block outside the flash area\n"); + return -EINVAL; + } + + patt_count = ARRAY_SIZE(patterns); + + buf = malloc(nand->erasesize); + if (buf == NULL) { + puts("Out of memory for erase block buffer\n"); + return -ENOMEM; + } + + for (i = 0; i < patt_count; i++) { + err = nand->erase(nand, &instr); + if (err) { + printf("%s: erase() failed for block at 0x%llx: %d\n", + nand->name, instr.addr, err); + goto out; + } + + /* Make sure the block contains only 0xff bytes */ + err = nand->read(nand, offset, nand->erasesize, &retlen, buf); + if ((err && err != -EUCLEAN) || retlen != nand->erasesize) { + printf("%s: read() failed for block at 0x%llx: %d\n", + nand->name, instr.addr, err); + goto out; + } + + err = check_pattern(buf, 0xff, nand->erasesize); + if (!err) { + printf("Erased block at 0x%llx, but a non-0xff byte was found\n", + offset); + ret = -EIO; + goto out; + } + + /* Write a pattern and check it */ + memset(buf, patterns[i], nand->erasesize); + err = nand->write(nand, offset, nand->erasesize, &retlen, buf); + if (err || retlen != nand->erasesize) { + printf("%s: write() failed for block at 0x%llx: %d\n", + nand->name, instr.addr, err); + goto out; + } + + err = nand->read(nand, offset, nand->erasesize, &retlen, buf); + if ((err && err != -EUCLEAN) || retlen != nand->erasesize) { + printf("%s: read() failed for block at 0x%llx: %d\n", + nand->name, instr.addr, err); + goto out; + } + + err = check_pattern(buf, patterns[i], nand->erasesize); + if (!err) { + printf("Pattern 0x%.2x checking failed for block at " + "0x%llx\n", patterns[i], offset); + ret = -EIO; + goto out; + } + } + + ret = 0; + +out: + free(buf); + return ret; +} + +#endif diff --git a/include/nand.h b/include/nand.h index bbe28b2..dded4e2 100644 --- a/include/nand.h +++ b/include/nand.h @@ -139,6 +139,7 @@ int nand_read_skip_bad(nand_info_t *nand, loff_t offset, size_t *length, int nand_write_skip_bad(nand_info_t *nand, loff_t offset, size_t *length, u_char *buffer, int flags); int nand_erase_opts(nand_info_t *meminfo, const nand_erase_options_t *opts); +int nand_torture(nand_info_t *nand, loff_t offset); #define NAND_LOCK_STATUS_TIGHT 0x01 #define NAND_LOCK_STATUS_UNLOCK 0x04 |