openwrtv3/target/linux/sunxi/patches-4.1/125-mtd-nand-sunxi-extend-bbt_options.patch

From a5ba30016f4a29f5875112169a92a28a9ba7f5c9 Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede@redhat.com>
Date: Mon, 25 May 2015 11:59:03 +0200
Subject: [PATCH] mtd: nand: sunxi: Add NAND_BBT_CREATE_EMPTY to bbt_options

The ftl format used by the Allwinner Android kernels, with which most
Allwinnner devices ship, overrides the factory bad block markers, and
fills the oob data with a pattern which causes a lot of false bad block
positives, so when we first create a bbt table, start with an empty one
to avoid marking a ton of blocks as bad from the start.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/mtd/nand/sunxi_nand.c | 9 +++++++++
 1 file changed, 9 insertions(+)

--- a/drivers/mtd/nand/sunxi_nand.c
+++ b/drivers/mtd/nand/sunxi_nand.c
@@ -1851,6 +1851,15 @@ static int sunxi_nand_chip_init(struct d
 	if (of_get_nand_on_flash_bbt(np))
 		nand->bbt_options |= NAND_BBT_USE_FLASH | NAND_BBT_NO_OOB;
 
+	/*
+	 * The ftl format used by the Allwinner Android kernels overrides
+	 * the factory bad block markers, and fills the oob data with a
+	 * pattern which causes a lot of false bad block positives, so
+	 * when we first create a bbt table, start with an empty one
+	 * to avoid marking a ton of blocks as bad from the start.
+	 */
+	nand->bbt_options |= NAND_BBT_CREATE_EMPTY;
+
 	mtd = &chip->mtd;
 	mtd->dev.parent = dev;
 	mtd->priv = nand;