nand: Add torture feature
This patch adds a NAND Flash torture feature, which is useful as a block stress
test to determine if a block is still good and reliable (or should be marked as
bad), e.g. after a write error.
This code is ported from mtd-utils' lib/libmtd.c.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Cc: Scott Wood <scottwood@freescale.com>
[scottwood@freescale.com: removed unnec. ifdef and unwrapped error strings]
Signed-off-by: Scott Wood <scottwood@freescale.com>
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 @@
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