From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932603AbaGOWAA (ORCPT ); Tue, 15 Jul 2014 18:00:00 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:54767 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759541AbaGOVh7 (ORCPT ); Tue, 15 Jul 2014 17:37:59 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Pekon Gupta , Brian Norris , Kamal Mostafa Subject: [PATCH 3.13 043/198] mtd: nand: omap: fix BCHx ecc.correct to return detected bit-flips in erased-page Date: Tue, 15 Jul 2014 14:28:33 -0700 Message-Id: <1405459868-15089-44-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1405459868-15089-1-git-send-email-kamal@canonical.com> References: <1405459868-15089-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.13.11.5 -stable review patch. If anyone has any objections, please let me know. ------------------ From: pekon gupta commit f306e8c3b667632952f1a4a74ffb910bbc06255f upstream. fixes: commit 62116e5171e00f85a8d53f76e45b84423c89ff34 mtd: nand: omap2: Support for hardware BCH error correction. In omap_elm_correct_data(), if bitflip_count in an erased-page is within the correctable limit (< ecc.strength), then it is not indicated back to the caller ecc->read_page(). This mis-guides upper layers like MTD and UBIFS layer to assume erased-page as perfectly clean and use it for writing even if actual bitflip_count was dangerously high (bitflip_count > mtd->bitflip_threshold). This patch fixes this above issue, by returning 'stats' to caller ecc->read_page() under all scenarios. Reported-by: Brian Norris Signed-off-by: Pekon Gupta Signed-off-by: Brian Norris Signed-off-by: Kamal Mostafa --- 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 2365b5a..b594e61 100644 --- a/drivers/mtd/nand/omap2.c +++ b/drivers/mtd/nand/omap2.c @@ -1451,7 +1451,7 @@ static int omap_elm_correct_data(struct mtd_info *mtd, u_char *data, /* Check if any error reported */ if (!is_error_reported) - return 0; + return stat; /* Decode BCH error using ELM module */ elm_decode_bch_error_page(info->elm_dev, ecc_vec, err_vec); -- 1.9.1