Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752261AbdGEGwJ (ORCPT ); Wed, 5 Jul 2017 02:52:09 -0400 Received: from mail.free-electrons.com ([62.4.15.54]:41947 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750796AbdGEGwI (ORCPT ); Wed, 5 Jul 2017 02:52:08 -0400 From: Miquel Raynal Cc: Miquel Raynal , Boris Brezillon , Richard Weinberger , David Woodhouse , Brian Norris , Marek Vasut , Cyrille Pitchen , linux-mtd@lists.infradead.org (open list:NAND FLASH SUBSYSTEM), linux-kernel@vger.kernel.org (open list) Subject: [PATCH] nand: fix wrong default oob layout for small pages using soft ecc Date: Wed, 5 Jul 2017 08:51:09 +0200 Message-Id: <20170705065109.7738-1-miquel.raynal@free-electrons.com> X-Mailer: git-send-email 2.11.0 To: unlisted-recipients:; (no To-header on input) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1849 Lines: 58 When using soft ecc, if no ooblayout is given, the core automatically uses one of the nand_ooblayout_{sp,lp}*() functions to determine the layout inside the out of band data. Until kernel version 4.6, struct nand_ecclayout was used for that purpose. During the migration from 4.6 to 4.7, an error shown up in the small page layout, in the case oob section is only 8 bytes long. The layout was using three bytes (0, 1, 2) for ecc, two bytes (3, 4) as free bytes, one byte (5) for bad block marker and finally two bytes (6, 7) as free bytes, as shown there: [linux-4.6] drivers/mtd/nand/nand_base.c:52 static struct nand_ecclayout nand_oob_8 = { .eccbytes = 3, .eccpos = {0, 1, 2}, .oobfree = { {.offset = 3, .length = 2}, {.offset = 6, .length = 2} } }; This fixes the current implementation which is incoherent. It references bit 3 at the same time as an ecc byte and a free byte. Furthermore, it is clear with the previous implementation that there is only one ecc section with 8 bytes oob sections. We shall return -ERANGE in the nand_ooblayout_ecc_sp() function when asked for the second section. Signed-off-by: Miquel Raynal --- drivers/mtd/nand/nand_base.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index b1dd12729f19..c5221795a1e8 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -65,8 +65,14 @@ static int nand_ooblayout_ecc_sp(struct mtd_info *mtd, int section, if (!section) { oobregion->offset = 0; - oobregion->length = 4; + if (mtd->oobsize == 16) + oobregion->length = 4; + else + oobregion->length = 3; } else { + if (mtd->oobsize == 8) + return -ERANGE; + oobregion->offset = 6; oobregion->length = ecc->total - 4; } -- 2.11.0