From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Roger Quadros , Tony Lindgren Subject: [PATCH 3.14 107/114] mtd: nand: omap: Fix 1-bit Hamming code scheme, omap_calculate_ecc() Date: Mon, 15 Sep 2014 12:26:47 -0700 Message-Id: <20140915192644.766988172@linuxfoundation.org> In-Reply-To: <20140915192641.428509513@linuxfoundation.org> References: <20140915192641.428509513@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Roger Quadros commit 40ddbf5069bd4e11447c0088fc75318e0aac53f0 upstream. commit 65b97cf6b8de introduced in v3.7 caused a regression by using a reversed CS_MASK thus causing omap_calculate_ecc to always fail. As the NAND base driver never checks for .calculate()'s return value, the zeroed ECC values are used as is without showing any error to the user. However, this won't work and the NAND device won't be guarded by any error code. Fix the issue by using the correct mask. Code was tested on omap3beagle using the following procedure - flash the primary bootloader (MLO) from the kernel to the first NAND partition using nandwrite. - boot the board from NAND. This utilizes OMAP ROM loader that relies on 1-bit Hamming code ECC. Fixes: 65b97cf6b8de (mtd: nand: omap2: handle nand on gpmc) Signed-off-by: Roger Quadros Signed-off-by: Tony Lindgren Signed-off-by: Greg Kroah-Hartman --- drivers/mtd/nand/omap2.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/mtd/nand/omap2.c +++ b/drivers/mtd/nand/omap2.c @@ -933,7 +933,7 @@ static int omap_calculate_ecc(struct mtd u32 val; val = readl(info->reg.gpmc_ecc_config); - if (((val >> ECC_CONFIG_CS_SHIFT) & ~CS_MASK) != info->gpmc_cs) + if (((val >> ECC_CONFIG_CS_SHIFT) & CS_MASK) != info->gpmc_cs) return -EINVAL; /* read ecc result */