From patchwork Wed Dec 2 11:01:05 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Boris BREZILLON X-Patchwork-Id: 7744571 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id B0B85BEEE1 for ; Wed, 2 Dec 2015 11:04:51 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id E706C20504 for ; Wed, 2 Dec 2015 11:04:50 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1BB9520511 for ; Wed, 2 Dec 2015 11:04:50 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1a45BU-0005jA-QR; Wed, 02 Dec 2015 11:02:52 +0000 Received: from down.free-electrons.com ([37.187.137.238] helo=mail.free-electrons.com) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1a45Az-0005RD-ST; Wed, 02 Dec 2015 11:02:23 +0000 Received: by mail.free-electrons.com (Postfix, from userid 110) id DC68F1F6; Wed, 2 Dec 2015 12:02:01 +0100 (CET) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Received: from localhost.localdomain (AToulouse-657-1-983-46.w86-217.abo.wanadoo.fr [86.217.137.46]) by mail.free-electrons.com (Postfix) with ESMTPSA id 8604D1C1A; Wed, 2 Dec 2015 12:01:10 +0100 (CET) From: Boris Brezillon To: David Woodhouse , Brian Norris , linux-mtd@lists.infradead.org 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> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20151202_030222_196467_94861D9A X-CRM114-Status: GOOD ( 10.34 ) X-Spam-Score: -2.6 (--) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Boris Brezillon , Chen-Yu Tsai , linux-kernel@vger.kernel.org, linux-sunxi@googlegroups.com, Maxime Ripard , linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP 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