From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757608AbbLBLCG (ORCPT ); Wed, 2 Dec 2015 06:02:06 -0500 Received: from down.free-electrons.com ([37.187.137.238]:35515 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756748AbbLBLCD (ORCPT ); Wed, 2 Dec 2015 06:02:03 -0500 From: Boris Brezillon To: David Woodhouse , Brian Norris , linux-mtd@lists.infradead.org Cc: Maxime Ripard , Chen-Yu Tsai , linux-sunxi@googlegroups.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Boris Brezillon Subject: [PATCH v2 1/3] mtd: nand: add NAND_NEED_SCRAMBLING option flag Date: Wed, 2 Dec 2015 12:01:05 +0100 Message-Id: <1449054067-16751-2-git-send-email-boris.brezillon@free-electrons.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1449054067-16751-1-git-send-email-boris.brezillon@free-electrons.com> References: <1449054067-16751-1-git-send-email-boris.brezillon@free-electrons.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: boris.brezillon@free-electrons.com (Boris Brezillon) Date: Wed, 2 Dec 2015 12:01:05 +0100 Subject: [PATCH v2 1/3] mtd: nand: add NAND_NEED_SCRAMBLING option flag In-Reply-To: <1449054067-16751-1-git-send-email-boris.brezillon@free-electrons.com> References: <1449054067-16751-1-git-send-email-boris.brezillon@free-electrons.com> Message-ID: <1449054067-16751-2-git-send-email-boris.brezillon@free-electrons.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 --- 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