mtd: nand: fix tmio_nand ecc correction

This driver may be reading 512 bytes at a times, but still calculates
256-byte sector ECC.  So the nand_correct_data() is not appropriate
for this driver.  Implement its ecc.correct function calling
__nand_correct_data() twice.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Acked-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Acked-by: Vimal Singh <vimalsingh@ti.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/nand/tmio_nand.c

@@ -301,6 +301,21 @@ static int tmio_nand_calculate_ecc(struct mtd_info *mtd, const u_char *dat,
 	return 0;
 }
 
+static int tmio_nand_correct_data(struct mtd_info *mtd, unsigned char *buf,
+		unsigned char *read_ecc, unsigned char *calc_ecc)
+{
+	int r0, r1;
+
+	/* assume ecc.size = 512 and ecc.bytes = 6 */
+	r0 = __nand_correct_data(buf, read_ecc, calc_ecc, 256);
+	if (r0 < 0)
+		return r0;
+	r1 = __nand_correct_data(buf + 256, read_ecc + 3, calc_ecc + 3, 256);
+	if (r1 < 0)
+		return r1;
+	return r0 + r1;
+}
+
 static int tmio_hw_init(struct platform_device *dev, struct tmio_nand *tmio)
 {
 	struct mfd_cell *cell = (struct mfd_cell *)dev->dev.platform_data;
@@ -424,7 +439,7 @@ static int tmio_probe(struct platform_device *dev)
 	nand_chip->ecc.bytes = 6;
 	nand_chip->ecc.hwctl = tmio_nand_enable_hwecc;
 	nand_chip->ecc.calculate = tmio_nand_calculate_ecc;
-	nand_chip->ecc.correct = nand_correct_data;
+	nand_chip->ecc.correct = tmio_nand_correct_data;
 
 	if (data)
 		nand_chip->badblock_pattern = data->badblock_pattern;