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From: Boris Brezillon <boris.brezillon@free-electrons.com>
To: David Woodhouse <dwmw2@infradead.org>,
	Brian Norris <computersforpeace@gmail.com>,
	linux-mtd@lists.infradead.org
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>,
	Chen-Yu Tsai <wens@csie.org>,
	linux-sunxi@googlegroups.com,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	Boris Brezillon <boris.brezillon@free-electrons.com>
Subject: [PATCH v2 1/3] mtd: nand: add NAND_NEED_SCRAMBLING option flag
Date: Wed,  2 Dec 2015 12:01:05 +0100	[thread overview]
Message-ID: <1449054067-16751-2-git-send-email-boris.brezillon@free-electrons.com> (raw)
In-Reply-To: <1449054067-16751-1-git-send-email-boris.brezillon@free-electrons.com>

Some MLC NANDs are sensitive to repeated patterns and require data to be
scrambled in order to limit the number of bitflips.
Add a new flag to let the NAND controller know about this constraint.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
 include/linux/mtd/nand.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index fad634e..0203b15 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -160,6 +160,12 @@ typedef enum {
 /* Device supports subpage reads */
 #define NAND_SUBPAGE_READ	0x00001000
 
+/*
+ * Some MLC NANDs need data scrambling to limit bitflips caused by repeated
+ * patterns.
+ */
+#define NAND_NEED_SCRAMBLING	0x00002000
+
 /* Options valid for Samsung large page devices */
 #define NAND_SAMSUNG_LP_OPTIONS NAND_CACHEPRG
 
-- 
2.1.4


  reply	other threads:[~2015-12-02 11:02 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-02 11:01 [PATCH v2 0/3] mtd: nand: add randomizer support Boris Brezillon
2015-12-02 11:01 ` Boris Brezillon [this message]
2015-12-02 11:01 ` [PATCH v2 2/3] mtd: nand: add NAND_NEED_SCRAMBLING flag to the H27UCG8T2ATR-BC definition Boris Brezillon
2015-12-02 11:01 ` [PATCH v2 3/3] mtd: nand: sunxi: add randomizer support Boris Brezillon
2016-01-23  2:57   ` Brian Norris
2016-01-23  8:18     ` Boris Brezillon
2016-01-23 20:55       ` Brian Norris
2016-01-11  9:13 ` [PATCH v2 0/3] mtd: nand: " Boris Brezillon

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