From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH] mtd: nand: omap: Fix 1-bit Hamming code scheme, omap_calculate_ecc() Date: Mon, 25 Aug 2014 09:47:07 -0700 Message-ID: <20140825164706.GK17254@atomide.com> References: <1407508028-12973-1-git-send-email-rogerq@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1407508028-12973-1-git-send-email-rogerq@ti.com> Sender: stable-owner@vger.kernel.org To: Roger Quadros Cc: computersforpeace@gmail.com, gregkh@linuxfoundation.org, nsekhar@ti.com, ezequiel.garcia@free-electrons.com, pekon@pek-sem.com, artem.bityutskiy@linux.intel.com, dwmw2@infradead.org, jg1.han@samsung.com, linux-mtd@lists.infradead.org, linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org List-Id: linux-omap@vger.kernel.org * Roger Quadros [140808 07:29]: > 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) > > Cc: [3.7+] > Signed-off-by: Roger Quadros I'll apply this into omap-for-v3.17/fixes thanks. Regards, Tony > --- > drivers/mtd/nand/omap2.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c > index f0ed92e..e2b9b34 100644 > --- a/drivers/mtd/nand/omap2.c > +++ b/drivers/mtd/nand/omap2.c > @@ -931,7 +931,7 @@ static int omap_calculate_ecc(struct mtd_info *mtd, const u_char *dat, > 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 */ > -- > 1.8.3.2 >