From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1162205Ab1FAJAP (ORCPT ); Wed, 1 Jun 2011 05:00:15 -0400 Received: from cantor.suse.de ([195.135.220.2]:44118 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1162139Ab1FAIR4 (ORCPT ); Wed, 1 Jun 2011 04:17:56 -0400 X-Mailbox-Line: From linux@blue.kroah.org Wed Jun 1 17:11:08 2011 Message-Id: <20110601081107.806560787@blue.kroah.org> User-Agent: quilt/0.48-16.4 Date: Wed, 01 Jun 2011 17:10:02 +0900 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Kishore Kadiyala , Vimal Singh , Artem Bityutskiy , David Woodhouse , Greg Kroah-Hartman Subject: [032/165] mtd: omap: fix subpage ecc issue with prefetch In-Reply-To: <20110601081349.GA10017@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.39-stable review patch. If anyone has any objections, please let us know. ------------------ Content-Length: 2505 Lines: 68 From: Kishore Kadiyala commit c5d8c0cae4af7d78823d32fcd1c458ee1a1b5489 upstream. When reading/writing a subpage (When HW ECC is not available/enabled) for number of bytes not aligned to 4, the mis-aligned bytes are handled first (by cpu copy method) before enabling the Prefetch engine to/from 'p'(start of buffer 'buf'). Then it reads/writes rest of the bytes with the help of Prefetch engine, if available, or again using cpu copy method. Currently, reading/writing of rest of bytes, is not done correctly since its trying to read/write again to/from begining of buffer 'buf', overwriting the mis-aligned bytes. Read & write using prefetch engine got broken in commit '2c01946c'. We never hit a scenario of not getting 'gpmc_prefetch_enable' call success. So, problem did not get caught up. Signed-off-by: Kishore Kadiyala Signed-off-by: Vimal Singh Reported-by: Bryan DE FARIA Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse Signed-off-by: Greg Kroah-Hartman --- drivers/mtd/nand/omap2.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) --- a/drivers/mtd/nand/omap2.c +++ b/drivers/mtd/nand/omap2.c @@ -263,11 +263,10 @@ static void omap_read_buf_pref(struct mt if (ret) { /* PFPW engine is busy, use cpu copy method */ if (info->nand.options & NAND_BUSWIDTH_16) - omap_read_buf16(mtd, buf, len); + omap_read_buf16(mtd, (u_char *)p, len); else - omap_read_buf8(mtd, buf, len); + omap_read_buf8(mtd, (u_char *)p, len); } else { - p = (u32 *) buf; do { r_count = gpmc_read_status(GPMC_PREFETCH_FIFO_CNT); r_count = r_count >> 2; @@ -293,7 +292,7 @@ static void omap_write_buf_pref(struct m struct omap_nand_info, mtd); uint32_t w_count = 0; int i = 0, ret = 0; - u16 *p; + u16 *p = (u16 *)buf; unsigned long tim, limit; /* take care of subpage writes */ @@ -309,11 +308,10 @@ static void omap_write_buf_pref(struct m if (ret) { /* PFPW engine is busy, use cpu copy method */ if (info->nand.options & NAND_BUSWIDTH_16) - omap_write_buf16(mtd, buf, len); + omap_write_buf16(mtd, (u_char *)p, len); else - omap_write_buf8(mtd, buf, len); + omap_write_buf8(mtd, (u_char *)p, len); } else { - p = (u16 *) buf; while (len) { w_count = gpmc_read_status(GPMC_PREFETCH_FIFO_CNT); w_count = w_count >> 1;