From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754262AbbBDLSM (ORCPT ); Wed, 4 Feb 2015 06:18:12 -0500 Received: from comal.ext.ti.com ([198.47.26.152]:51852 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751033AbbBDLSH (ORCPT ); Wed, 4 Feb 2015 06:18:07 -0500 Message-ID: <54D1FFC5.3030901@ti.com> Date: Wed, 4 Feb 2015 13:17:25 +0200 From: Roger Quadros User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: Nicholas Mc Guire , Brian Norris CC: David Woodhouse , Ezequiel Garcia , Tony Lindgren , Rostislav Lisovy , , , pekon Subject: Re: [PATCH] mtd: nand: omap: conditions with no effect References: <1423042059-22416-1-git-send-email-hofrat@osadl.org> In-Reply-To: <1423042059-22416-1-git-send-email-hofrat@osadl.org> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Nicholas, On 04/02/15 11:27, Nicholas Mc Guire wrote: > The if and the else branch code are identical - so the condition has no > effect on the effective code - this patch removes the condition and the > duplicated code. > > Signed-off-by: Nicholas Mc Guire > --- > > The conditions in the OMAP_ECC_BCH8_CODE_HW_DETECTION_SW and > OMAP_ECC_BCH4_CODE_HW_DETECTION_SW case have no effect and can > be removed. As there are no comments it is not possible to say > if this is the correct solution or if this is actually a bug and > the two branches should be different. > > This patch needs a review by someone who knows the details of the driver > > Patch was only compile tested with arm-linux-gnueabi-4.7-, current > crosstool-ng did no not seem to compile omap2 properly. > Config is omap2plus_defconfig which implies CONFIG_MTD_NAND_OMAP2=y. > > Patch is against 3.19.0-rc6 (localversion-next is -next-20150203) > > drivers/mtd/nand/omap2.c | 24 ++++++------------------ > 1 file changed, 6 insertions(+), 18 deletions(-) Your patch is correct as far as I can tell based on commits 2ef9f3ddec55, 62116e5171e0 and 8d602cf50d3b. The idea was to use BCH_WRAPMODE_6 for both reads and writes when we're not using the ELM module for error correction. i.e. BCH4_SW or BCH8_SW. This is mentioned in the header of omap_enable_hwecc_bch() but it is not very clear. So let's fix that as well with this patch. diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c index 63f858e..a133780 100644 --- a/drivers/mtd/nand/omap2.c +++ b/drivers/mtd/nand/omap2.c @@ -1048,10 +1048,9 @@ static int omap_dev_ready(struct mtd_info *mtd) * @mtd: MTD device structure * @mode: Read/Write mode * - * When using BCH, sector size is hardcoded to 512 bytes. - * Using wrapping mode 6 both for reading and writing if ELM module not uses - * for error correction. - * On writing, + * When using BCH with SW correction (i.e. no ELM), sector size is set + * to 512 bytes and we use BCH_WRAPMODE_6 wrapping mode + * for both reading and writing with: * eccsize0 = 0 (no additional protected byte in spare area) * eccsize1 = 32 (skip 32 nibbles = 16 bytes per sector in spare area) */ Then you can also add my Acked-by: Roger Quadros cheers, -roger > > diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c > index 63f858e..5bcdd66 100644 > --- a/drivers/mtd/nand/omap2.c > +++ b/drivers/mtd/nand/omap2.c > @@ -1071,15 +1071,9 @@ static void __maybe_unused omap_enable_hwecc_bch(struct mtd_info *mtd, int mode) > case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW: > bch_type = 0; > nsectors = 1; > - if (mode == NAND_ECC_READ) { > - wr_mode = BCH_WRAPMODE_6; > - ecc_size0 = BCH_ECC_SIZE0; > - ecc_size1 = BCH_ECC_SIZE1; > - } else { > - wr_mode = BCH_WRAPMODE_6; > - ecc_size0 = BCH_ECC_SIZE0; > - ecc_size1 = BCH_ECC_SIZE1; > - } > + wr_mode = BCH_WRAPMODE_6; > + ecc_size0 = BCH_ECC_SIZE0; > + ecc_size1 = BCH_ECC_SIZE1; > break; > case OMAP_ECC_BCH4_CODE_HW: > bch_type = 0; > @@ -1097,15 +1091,9 @@ static void __maybe_unused omap_enable_hwecc_bch(struct mtd_info *mtd, int mode) > case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW: > bch_type = 1; > nsectors = 1; > - if (mode == NAND_ECC_READ) { > - wr_mode = BCH_WRAPMODE_6; > - ecc_size0 = BCH_ECC_SIZE0; > - ecc_size1 = BCH_ECC_SIZE1; > - } else { > - wr_mode = BCH_WRAPMODE_6; > - ecc_size0 = BCH_ECC_SIZE0; > - ecc_size1 = BCH_ECC_SIZE1; > - } > + wr_mode = BCH_WRAPMODE_6; > + ecc_size0 = BCH_ECC_SIZE0; > + ecc_size1 = BCH_ECC_SIZE1; > break; > case OMAP_ECC_BCH8_CODE_HW: > bch_type = 1; >