[PATCH 1/3] mtd: rawnand: Add a NAND_NO_BBM_QUIRK flag

[Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>]

Some controllers with embedded ECC engines override the BBM marker with
data or ECC bytes, thus making bad block detection through bad block
marker impossible. Let's flag those chips so the core knows it shouldn't
check the BBM and consider all blocks good.

This should allow us to get rid of two implementers of the
legacy.block_bad() hook.

Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
---
 drivers/mtd/nand/raw/nand_base.c | 3 +++
 include/linux/mtd/rawnand.h      | 8 ++++++++
 2 files changed, 11 insertions(+)

diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
index f81b54634061..749ef0b40684 100644
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -345,6 +345,9 @@ static int nand_block_bad(struct nand_chip *chip, loff_t ofs)
 
 static int nand_isbad_bbm(struct nand_chip *chip, loff_t ofs)
 {
+	if (chip->options & NAND_NO_BBM_QUIRK)
+		return 0;
+
 	if (chip->legacy.block_bad)
 		return chip->legacy.block_bad(chip, ofs);
 
diff --git a/include/linux/mtd/rawnand.h b/include/linux/mtd/rawnand.h
index 99f4ac47c8d3..37613dd9e04b 100644
--- a/include/linux/mtd/rawnand.h
+++ b/include/linux/mtd/rawnand.h
@@ -222,6 +222,14 @@ enum nand_ecc_algo {
  */
 #define NAND_KEEP_TIMINGS	0x00800000
 
+/*
+ * Some controllers with pipelined ECC engines override the BBM marker with
+ * data or ECC bytes, thus making bad block detection through bad block marker
+ * impossible. Let's flag those chips so the core knows it shouldn't check the
+ * BBM and consider all blocks good.
+ */
+#define NAND_NO_BBM_QUIRK	0
+
 /* Cell info constants */
 #define NAND_CI_CHIPNR_MSK	0x03
 #define NAND_CI_CELLTYPE_MSK	0x0C
-- 
2.25.3


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