[PATCH v2] mtd: nand: Mark reserved blocks

[Ashok Reddy Soma <ashok.reddy.soma@amd.com>]

Reserved blocks are used for storing bad block tables. With "nand bad"
command, these reserved blocks are shown as bad blocks. This is leading
to confusion when compared with Linux bad blocks. Hence, display
"bbt reserved" when printing reserved blocks with "nand bad" command.

To acheive this, return 2 which represents reserved from nand_isbad_bbt()
instead of 1 in case of reserved blocks and catch it in cmd/nand.c.

"nand bad" command display's hexadecimal numbers, so add "0x" prefix.

Example log will show up as below.

ZynqMP> nand bad

Device 0 bad blocks:
  0x00400000
  0x16800000
  0x16c00000
  0x17000000
  0x3d800000
  0x3e400000
  0xe8400000
  0xff000000	 (bbt reserved)
  0xff400000	 (bbt reserved)
  0xff800000	 (bbt reserved)
  0xffc00000	 (bbt reserved)
  0x116800000
  0x116c00000
  0x1ff000000	 (bbt reserved)
  0x1ff400000	 (bbt reserved)
  0x1ff800000	 (bbt reserved)
  0x1ffc00000	 (bbt reserved)

Signed-off-by: Ashok Reddy Soma <ashok.reddy.soma@amd.com>
Reviewed-by: Michael Trimarchi <michael@amarulasolutions.com>
---

Changes in v2:
 - Changed "Reserved for bbt" to (bbt reserved)
 - Updated description and the log in the description

 cmd/nand.c                      | 9 ++++++---
 drivers/mtd/nand/raw/nand_bbt.c | 3 ++-
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/cmd/nand.c b/cmd/nand.c
index 9a723f5757..b41e54ec42 100644
--- a/cmd/nand.c
+++ b/cmd/nand.c
@@ -567,9 +567,12 @@ static int do_nand(struct cmd_tbl *cmdtp, int flag, int argc,
 
 	if (strcmp(cmd, "bad") == 0) {
 		printf("\nDevice %d bad blocks:\n", dev);
-		for (off = 0; off < mtd->size; off += mtd->erasesize)
-			if (nand_block_isbad(mtd, off))
-				printf("  %08llx\n", (unsigned long long)off);
+		for (off = 0; off < mtd->size; off += mtd->erasesize) {
+			ret = nand_block_isbad(mtd, off);
+			if (ret)
+				printf("  0x%08llx%s\n", (unsigned long long)off,
+				       ret == 2 ? "\t (bbt reserved)" : "");
+		}
 		return 0;
 	}
 
diff --git a/drivers/mtd/nand/raw/nand_bbt.c b/drivers/mtd/nand/raw/nand_bbt.c
index 911472e91e..cd451870a6 100644
--- a/drivers/mtd/nand/raw/nand_bbt.c
+++ b/drivers/mtd/nand/raw/nand_bbt.c
@@ -1330,6 +1330,7 @@ int nand_isreserved_bbt(struct mtd_info *mtd, loff_t offs)
  * @mtd: MTD device structure
  * @offs: offset in the device
  * @allowbbt: allow access to bad block table region
+ * Return: 0 - good block, 1- bad block, 2 - reserved block
  */
 int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt)
 {
@@ -1348,7 +1349,7 @@ int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt)
 	case BBT_BLOCK_WORN:
 		return 1;
 	case BBT_BLOCK_RESERVED:
-		return allowbbt ? 0 : 1;
+		return allowbbt ? 0 : 2;
 	}
 	return 1;
 }
-- 
2.17.1