From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754682AbdBETnz (ORCPT + 2 others); Sun, 5 Feb 2017 14:43:55 -0500 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:28348 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754436AbdBET1E (ORCPT ); Sun, 5 Feb 2017 14:27:04 -0500 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net Cc: Karl Beldan , Brian Norris , Willy Tarreau Subject: [PATCH 3.10 209/319] mtd: nand: davinci: Reinitialize the HW ECC engine in 4bit hwctl Date: Sun, 5 Feb 2017 20:20:31 +0100 Message-Id: <1486322541-8206-110-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1486322541-8206-1-git-send-email-w@1wt.eu> References: <1486322541-8206-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: From: Karl Beldan commit f6d7c1b5598b6407c3f1da795dd54acf99c1990c upstream. This fixes subpage writes when using 4-bit HW ECC. There has been numerous reports about ECC errors with devices using this driver for a while. Also the 4-bit ECC has been reported as broken with subpages in [1] and with 16 bits NANDs in the driver and in mach* board files both in mainline and in the vendor BSPs. What I saw with 4-bit ECC on a 16bits NAND (on an LCDK) which got me to try reinitializing the ECC engine: - R/W on whole pages properly generates/checks RS code - try writing the 1st subpage only of a blank page, the subpage is well written and the RS code properly generated, re-reading the same page the HW detects some ECC error, reading the same page again no ECC error is detected Note that the ECC engine is already reinitialized in the 1-bit case. Tested on my LCDK with UBI+UBIFS using subpages. This could potentially get rid of the issue workarounded in [1]. [1] 28c015a9daab ("mtd: davinci-nand: disable subpage write for keystone-nand") Fixes: 6a4123e581b3 ("mtd: nand: davinci_nand, 4-bit ECC for smallpage") Signed-off-by: Karl Beldan Acked-by: Boris Brezillon Signed-off-by: Brian Norris Signed-off-by: Willy Tarreau --- drivers/mtd/nand/davinci_nand.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/mtd/nand/davinci_nand.c b/drivers/mtd/nand/davinci_nand.c index c3e15a5..e4f16cf 100644 --- a/drivers/mtd/nand/davinci_nand.c +++ b/drivers/mtd/nand/davinci_nand.c @@ -241,6 +241,9 @@ static void nand_davinci_hwctl_4bit(struct mtd_info *mtd, int mode) unsigned long flags; u32 val; + /* Reset ECC hardware */ + davinci_nand_readl(info, NAND_4BIT_ECC1_OFFSET); + spin_lock_irqsave(&davinci_nand_lock, flags); /* Start 4-bit ECC calculation for read/write */ -- 2.8.0.rc2.1.gbe9624a