[RFC PATCH] arm: mach-imx: cmd_nandbcb fix bad block handling

[Michael Trimarchi]

The badblock should be skipped properly in reading and writing.
Fix the logic

NOTE. This is a rfc. Working on imx8mn and found the bad block
handling in nand is quite broken. Seems that bootrom does not handle
it so I switch on spl nand bad block and found there other bugs. I have
fixed most of them. Let's start in how to read back the nandbcb

Signed-off-by: Michael Trimarchi <michael at amarulasolutions.com>
---
 arch/arm/mach-imx/cmd_nandbcb.c | 21 +++++++--------------
 1 file changed, 7 insertions(+), 14 deletions(-)

diff --git a/arch/arm/mach-imx/cmd_nandbcb.c b/arch/arm/mach-imx/cmd_nandbcb.c
index 100dc17a15..48955092b7 100644
--- a/arch/arm/mach-imx/cmd_nandbcb.c
+++ b/arch/arm/mach-imx/cmd_nandbcb.c
@@ -505,10 +505,6 @@ static int read_fcb(struct boot_config *boot_cfg, struct fcb_block *fcb,
 	int ret = 0;
 
 	mtd = boot_cfg->mtd;
-	if (mtd_block_isbad(mtd, off)) {
-		printf("Block %d is bad, skipped\n", (int)CONV_TO_BLOCKS(off));
-		return 1;
-	}
 
 	fcb_raw_page = kzalloc(mtd->writesize + mtd->oobsize, GFP_KERNEL);
 	if (!fcb_raw_page) {
@@ -529,7 +525,7 @@ static int read_fcb(struct boot_config *boot_cfg, struct fcb_block *fcb,
 		else if (plat_config.misc_flags & FCB_ENCODE_BCH_40b)
 			mxs_nand_mode_fcb_40bit(mtd);
 
-		ret = nand_read(mtd, off, &size, (u_char *)fcb);
+		ret = nand_read_skip_bad(mtd, off, &size, NULL, mtd->size, (u_char *)fcb);
 
 		/* switch BCH back */
 		mxs_nand_mode_normal(mtd);
@@ -616,6 +612,7 @@ static int write_fcb(struct boot_config *boot_cfg, struct fcb_block *fcb)
 	for (i = 0; i < g_boot_search_count; i++) {
 		if (mtd_block_isbad(mtd, off)) {
 			printf("Block %d is bad, skipped\n", i);
+			off += mtd->erasesize;
 			continue;
 		}
 
@@ -675,20 +672,15 @@ static int read_dbbt(struct boot_config *boot_cfg, struct dbbt_block *dbbt,
 		      void *dbbt_data_page, loff_t off)
 {
 	size_t size;
+	size_t actual_size;
 	struct mtd_info *mtd;
 	loff_t to;
 	int ret;
 
 	mtd = boot_cfg->mtd;
 
-	if (mtd_block_isbad(mtd, off)) {
-		printf("Block %d is bad, skipped\n",
-		       (int)CONV_TO_BLOCKS(off));
-		return 1;
-	}
-
 	size = sizeof(struct dbbt_block);
-	ret = nand_read(mtd, off, &size, (u_char *)dbbt);
+	ret = nand_read_skip_bad(mtd, off, &size, &actual_size, mtd->size, (u_char *)dbbt);
 	printf("NAND DBBT read from 0x%llx offset 0x%zx read: %s\n",
 	       off, size, ret ? "ERROR" : "OK");
 	if (ret)
@@ -696,9 +688,9 @@ static int read_dbbt(struct boot_config *boot_cfg, struct dbbt_block *dbbt,
 
 	/* dbbtpages == 0 if no bad blocks */
 	if (dbbt->dbbtpages > 0) {
-		to = off + 4 * mtd->writesize;
+		to = off + 4 * mtd->writesize + actual_size - size;
 		size = mtd->writesize;
-		ret = nand_read(mtd, to, &size, dbbt_data_page);
+		ret = nand_read_skip_bad(mtd, to, &size, NULL, mtd->size, dbbt_data_page);
 		printf("DBBT data read from 0x%llx offset 0x%zx read: %s\n",
 		       to, size, ret ? "ERROR" : "OK");
 
@@ -728,6 +720,7 @@ static int write_dbbt(struct boot_config *boot_cfg, struct dbbt_block *dbbt,
 		if (mtd_block_isbad(mtd, off)) {
 			printf("Block %d is bad, skipped\n",
 			       (int)(i + CONV_TO_BLOCKS(off)));
+			off += mtd->erasesize;
 			continue;
 		}
 
-- 
2.25.1