From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752700AbbKQAkK (ORCPT ); Mon, 16 Nov 2015 19:40:10 -0500 Received: from mail-pa0-f52.google.com ([209.85.220.52]:33460 "EHLO mail-pa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750865AbbKQAkI (ORCPT ); Mon, 16 Nov 2015 19:40:08 -0500 Date: Mon, 16 Nov 2015 16:40:05 -0800 From: Brian Norris To: Simon Arlott Cc: David Woodhouse , linux-mtd@lists.infradead.org, Linux Kernel Mailing List , Kevin Cernekee , bcm-kernel-feedback-list@broadcom.com Subject: Re: [PATCH] brcmnand: Clear EXT_ADDR error registers in PIO mode Message-ID: <20151117004005.GU8456@google.com> References: <564A5333.9000200@simon.arlott.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <564A5333.9000200@simon.arlott.org.uk> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org + bcm-kernel-feedback-list On Mon, Nov 16, 2015 at 10:05:39PM +0000, Simon Arlott wrote: > If an error occurs in flash above 4GB in PIO mode then the EXT_ADDR > registers will be set to the location of the error and never cleared. > > Reset them to 0 before reading. > > Signed-off-by: Simon Arlott Patch looks OK. Did you see this problem in practice, or is this just theoretical? I thought the documentation seemed to suggest these registers were cleared together with their non-_EXT counterparts. But implementation definitely trumps documentation for HW. Brian > --- > drivers/mtd/nand/brcmnand/brcmnand.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/mtd/nand/brcmnand/brcmnand.c b/drivers/mtd/nand/brcmnand/brcmnand.c > index 12c6190..2c8f67f 100644 > --- a/drivers/mtd/nand/brcmnand/brcmnand.c > +++ b/drivers/mtd/nand/brcmnand/brcmnand.c > @@ -1400,6 +1400,8 @@ static int brcmnand_read_by_pio(struct mtd_info *mtd, struct nand_chip *chip, > /* Clear error addresses */ > brcmnand_write_reg(ctrl, BRCMNAND_UNCORR_ADDR, 0); > brcmnand_write_reg(ctrl, BRCMNAND_CORR_ADDR, 0); > + brcmnand_write_reg(ctrl, BRCMNAND_UNCORR_EXT_ADDR, 0); > + brcmnand_write_reg(ctrl, BRCMNAND_CORR_EXT_ADDR, 0); > > brcmnand_write_reg(ctrl, BRCMNAND_CMD_EXT_ADDRESS, > (host->cs << 16) | ((addr >> 32) & 0xffff)); > -- > 2.1.4 > > -- > Simon Arlott