mtd: nand: erase block before marking bad

Many NAND flash systems (especially those with MLC NAND) cannot be
reliably written twice in a row. For instance, when marking a bad block,
the block may already have data written to it, and so we should attempt
to erase the block before writing a bad block marker to its OOB region.

We can ignore erase failures, since the block may be bad such that it
cannot be erased properly; we still attempt to write zeros to its spare
area.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 8a393f9e6027..cd827d5a8255 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -394,6 +394,17 @@ static int nand_default_block_markbad(struct mtd_info *mtd, loff_t ofs)
         uint8_t buf[2] = { 0, 0 };
         int block, ret, i = 0;
 
+        if (!(chip->bbt_options & NAND_BBT_USE_FLASH)) {
+                struct erase_info einfo;
+
+                /* Attempt erase before marking OOB */
+                memset(&einfo, 0, sizeof(einfo));
+                einfo.mtd = mtd;
+                einfo.addr = ofs;
+                einfo.len = 1 << chip->phys_erase_shift;
+                nand_erase_nand(mtd, &einfo, 0);
+        }
+
         if (chip->bbt_options & NAND_BBT_SCANLASTPAGE)
                 ofs += mtd->erasesize - mtd->writesize;