435 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			435 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| From ian@brightstareng.com Fri May 18 15:06:49 2007
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| From ian@brightstareng.com Fri May 18 15:08:21 2007
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| Received: from 206.173.66.57.ptr.us.xo.net ([206.173.66.57] helo=zebra.brightstareng.com)
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| 	by apollo.linkchoose.co.uk with esmtp (Exim 4.60)
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| 	(envelope-from <ian@brightstareng.com>)
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| 	id 1Hp380-00011e-T6
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| 	for david.goodenough@linkchoose.co.uk; Fri, 18 May 2007 15:08:21 +0100
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| Received: from localhost (localhost.localdomain [127.0.0.1])
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| 	by zebra.brightstareng.com (Postfix) with ESMTP
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| 	id 4819F28C004; Fri, 18 May 2007 10:07:49 -0400 (EDT)
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| Received: from zebra.brightstareng.com ([127.0.0.1])
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|  by localhost (zebra [127.0.0.1]) (amavisd-new, port 10024) with ESMTP
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|  id 05328-06; Fri, 18 May 2007 10:07:16 -0400 (EDT)
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| Received: from pippin (unknown [192.168.1.25])
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| 	by zebra.brightstareng.com (Postfix) with ESMTP
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| 	id 8BEF528C1BC; Fri, 18 May 2007 10:06:53 -0400 (EDT)
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| From: Ian McDonnell <ian@brightstareng.com>
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| To: David Goodenough <david.goodenough@linkchoose.co.uk>
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| Subject: Re: something tested this time -- yaffs_mtdif1-compat.c
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| Date: Fri, 18 May 2007 10:06:49 -0400
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| User-Agent: KMail/1.9.1
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| References: <200705142207.06909.ian@brightstareng.com> <200705171131.53536.ian@brightstareng.com> <200705181334.32166.david.goodenough@linkchoose.co.uk>
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| In-Reply-To: <200705181334.32166.david.goodenough@linkchoose.co.uk>
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| Cc: Andrea Conti <alyf@alyf.net>,
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|  Charles Manning <manningc2@actrix.gen.nz>
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| MIME-Version: 1.0
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| Message-Id: <200705181006.49860.ian@brightstareng.com>
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| Status: R
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| 
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| --Boundary-00=_5LbTGmt62YoutxM
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| Content-Type: text/plain;
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|   charset="iso-8859-15"
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| Content-Transfer-Encoding: 7bit
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| Content-Disposition: inline
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| 
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| David, Andrea,
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| 
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| On Friday 18 May 2007 08:34, you wrote:
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| > Yea team.  With this fix in place (I put it in the wrong place
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| > at first) I can now mount and ls the Yaffs partition without
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| > an error messages!
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| 
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| Good news!
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| 
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| Attached is a newer yaffs_mtdif1.c with a bandaid to help the
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| 2.6.18 and 2.6.19 versions of MTD not trip on the oob read.
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| See the LINUX_VERSION_CODE conditional in
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| nandmtd1_ReadChunkWithTagsFromNAND.
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| 
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| -imcd
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| 
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| --Boundary-00=_5LbTGmt62YoutxM
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| Content-Type: text/x-csrc;
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|   charset="iso-8859-15";
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|   name="yaffs_mtdif1.c"
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| Content-Transfer-Encoding: 7bit
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| Content-Disposition: attachment;
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| 	filename="yaffs_mtdif1.c"
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| 
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| /*
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|  * YAFFS: Yet another FFS. A NAND-flash specific file system.
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|  * yaffs_mtdif1.c  NAND mtd interface functions for small-page NAND.
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|  *
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|  * Copyright (C) 2002 Aleph One Ltd.
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|  *   for Toby Churchill Ltd and Brightstar Engineering
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|  *
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|  * This program is free software; you can redistribute it and/or modify
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|  * it under the terms of the GNU General Public License version 2 as
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|  * published by the Free Software Foundation.
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|  */
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| 
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| /*
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|  * This module provides the interface between yaffs_nand.c and the
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|  * MTD API.  This version is used when the MTD interface supports the
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|  * 'mtd_oob_ops' style calls to read_oob and write_oob, circa 2.6.17,
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|  * and we have small-page NAND device.
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|  *
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|  * These functions are invoked via function pointers in yaffs_nand.c.
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|  * This replaces functionality provided by functions in yaffs_mtdif.c
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|  * and the yaffs_TagsCompatability functions in yaffs_tagscompat.c that are
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|  * called in yaffs_mtdif.c when the function pointers are NULL.
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|  * We assume the MTD layer is performing ECC (useNANDECC is true).
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|  */
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| 
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| #include "yportenv.h"
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| #include "yaffs_guts.h"
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| #include "yaffs_packedtags1.h"
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| #include "yaffs_tagscompat.h"	// for yaffs_CalcTagsECC
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| 
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| #include "linux/kernel.h"
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| #include "linux/version.h"
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| #include "linux/types.h"
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| #include "linux/mtd/mtd.h"
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| 
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| /* Don't compile this module if we don't have MTD's mtd_oob_ops interface */
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| #if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
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| 
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| const char *yaffs_mtdif1_c_version = "$Id$";
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| 
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| #ifndef CONFIG_YAFFS_9BYTE_TAGS
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| # define YTAG1_SIZE 8
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| #else
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| # define YTAG1_SIZE 9
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| #endif
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| 
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| #if 0
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| /* Use the following nand_ecclayout with MTD when using
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|  * CONFIG_YAFFS_9BYTE_TAGS and the older on-NAND tags layout.
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|  * If you have existing Yaffs images and the byte order differs from this,
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|  * adjust 'oobfree' to match your existing Yaffs data.
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|  *
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|  * This nand_ecclayout scatters/gathers to/from the old-yaffs layout with the
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|  * pageStatus byte (at NAND spare offset 4) scattered/gathered from/to
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|  * the 9th byte.
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|  *
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|  * Old-style on-NAND format: T0,T1,T2,T3,P,B,T4,T5,E0,E1,E2,T6,T7,E3,E4,E5
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|  * We have/need PackedTags1 plus pageStatus: T0,T1,T2,T3,T4,T5,T6,T7,P
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|  * where Tn are the tag bytes, En are MTD's ECC bytes, P is the pageStatus
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|  * byte and B is the small-page bad-block indicator byte.
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|  */
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| static struct nand_ecclayout nand_oob_16 = {
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| 	.eccbytes = 6,
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| 	.eccpos = { 8, 9, 10, 13, 14, 15 },
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| 	.oobavail = 9,
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| 	.oobfree = { { 0, 4 }, { 6, 2 }, { 11, 2 }, { 4, 1 } }
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| };
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| #endif
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| 
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| /* Write a chunk (page) of data to NAND.
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|  *
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|  * Caller always provides ExtendedTags data which are converted to a more
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|  * compact (packed) form for storage in NAND.  A mini-ECC runs over the
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|  * contents of the tags meta-data; used to valid the tags when read.
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|  *
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|  *  - Pack ExtendedTags to PackedTags1 form
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|  *  - Compute mini-ECC for PackedTags1
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|  *  - Write data and packed tags to NAND.
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|  *
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|  * Note: Due to the use of the PackedTags1 meta-data which does not include
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|  * a full sequence number (as found in the larger PackedTags2 form) it is
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|  * necessary for Yaffs to re-write a chunk/page (just once) to mark it as
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|  * discarded and dirty.  This is not ideal: newer NAND parts are supposed
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|  * to be written just once.  When Yaffs performs this operation, this
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|  * function is called with a NULL data pointer -- calling MTD write_oob
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|  * without data is valid usage (2.6.17).
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|  *
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|  * Any underlying MTD error results in YAFFS_FAIL.
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|  * Returns YAFFS_OK or YAFFS_FAIL.
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|  */
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| int nandmtd1_WriteChunkWithTagsToNAND(yaffs_Device *dev,
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| 	int chunkInNAND, const __u8 * data, const yaffs_ExtendedTags * etags)
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| {
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| 	struct mtd_info * mtd = dev->genericDevice;
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| 	int chunkBytes = dev->nDataBytesPerChunk;
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| 	loff_t addr = ((loff_t)chunkInNAND) * chunkBytes;
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| 	struct mtd_oob_ops ops;
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| 	yaffs_PackedTags1 pt1;
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| 	int retval;
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| 
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| 	/* we assume that PackedTags1 and yaffs_Tags are compatible */
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| 	compile_time_assertion(sizeof(yaffs_PackedTags1) == 12);
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| 	compile_time_assertion(sizeof(yaffs_Tags) == 8);
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| 
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| 	yaffs_PackTags1(&pt1, etags);
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| 	yaffs_CalcTagsECC((yaffs_Tags *)&pt1);
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| 
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| 	/* When deleting a chunk, the upper layer provides only skeletal
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| 	 * etags, one with chunkDeleted set.  However, we need to update the
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| 	 * tags, not erase them completely.  So we use the NAND write property
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| 	 * that only zeroed-bits stick and set tag bytes to all-ones and
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| 	 * zero just the (not) deleted bit.
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| 	 */
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| #ifndef CONFIG_YAFFS_9BYTE_TAGS
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| 	if (etags->chunkDeleted) {
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| 		memset(&pt1, 0xff, 8);
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| 		/* clear delete status bit to indicate deleted */
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| 		pt1.deleted = 0;
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| 	}
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| #else
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| 	((__u8 *)&pt1)[8] = 0xff;
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| 	if (etags->chunkDeleted) {
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| 		memset(&pt1, 0xff, 8);
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| 		/* zero pageStatus byte to indicate deleted */
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| 		((__u8 *)&pt1)[8] = 0;
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| 	}
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| #endif
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| 
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| 	memset(&ops, 0, sizeof(ops));
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| 	ops.mode = MTD_OOB_AUTO;
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| 	ops.len = (data) ? chunkBytes : 0;
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| 	ops.ooblen = YTAG1_SIZE;
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| 	ops.datbuf = (__u8 *)data;
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| 	ops.oobbuf = (__u8 *)&pt1;
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| 
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| 	retval = mtd->write_oob(mtd, addr, &ops);
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| 	if (retval) {
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| 		yaffs_trace(YAFFS_TRACE_MTD,
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| 			"write_oob failed, chunk %d, mtd error %d\n",
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| 			chunkInNAND, retval);
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| 	}
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| 	return retval ? YAFFS_FAIL : YAFFS_OK;
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| }
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| 
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| /* Return with empty ExtendedTags but add eccResult.
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|  */
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| static int rettags(yaffs_ExtendedTags * etags, int eccResult, int retval)
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| {
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| 	if (etags) {
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| 		memset(etags, 0, sizeof(*etags));
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| 		etags->eccResult = eccResult;
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| 	}
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| 	return retval;
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| }
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| 
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| /* Read a chunk (page) from NAND.
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|  *
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|  * Caller expects ExtendedTags data to be usable even on error; that is,
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|  * all members except eccResult and blockBad are zeroed.
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|  *
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|  *  - Check ECC results for data (if applicable)
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|  *  - Check for blank/erased block (return empty ExtendedTags if blank)
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|  *  - Check the PackedTags1 mini-ECC (correct if necessary/possible)
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|  *  - Convert PackedTags1 to ExtendedTags
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|  *  - Update eccResult and blockBad members to refect state.
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|  *
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|  * Returns YAFFS_OK or YAFFS_FAIL.
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|  */
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| int nandmtd1_ReadChunkWithTagsFromNAND(yaffs_Device *dev,
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| 	int chunkInNAND, __u8 * data, yaffs_ExtendedTags * etags)
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| {
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| 	struct mtd_info * mtd = dev->genericDevice;
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| 	int chunkBytes = dev->nDataBytesPerChunk;
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| 	loff_t addr = ((loff_t)chunkInNAND) * chunkBytes;
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| 	int eccres = YAFFS_ECC_RESULT_NO_ERROR;
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| 	struct mtd_oob_ops ops;
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| 	yaffs_PackedTags1 pt1;
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| 	int retval;
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| 	int deleted;
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| 
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| 	memset(&ops, 0, sizeof(ops));
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| 	ops.mode = MTD_OOB_AUTO;
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| 	ops.len = (data) ? chunkBytes : 0;
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| 	ops.ooblen = YTAG1_SIZE;
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| 	ops.datbuf = data;
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| 	ops.oobbuf = (__u8 *)&pt1;
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| 
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| #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20))
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| 	/* In MTD 2.6.18 to 2.6.19 nand_base.c:nand_do_read_oob() has a bug;
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| 	 * help it out with ops.len = ops.ooblen when ops.datbuf == NULL.
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| 	 */
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| 	ops.len = (ops.datbuf) ? ops.len : ops.ooblen;
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| #endif
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| 	/* Read page and oob using MTD.
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| 	 * Check status and determine ECC result.
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| 	 */
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| 	retval = mtd->read_oob(mtd, addr, &ops);
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| 	if (retval) {
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| 		yaffs_trace(YAFFS_TRACE_MTD,
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| 			"read_oob failed, chunk %d, mtd error %d\n",
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| 			chunkInNAND, retval);
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| 	}
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| 
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| 	switch (retval) {
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| 	case 0:
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| 		/* no error */
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| 		break;
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| 
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| 	case -EUCLEAN:
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| 		/* MTD's ECC fixed the data */
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| 		eccres = YAFFS_ECC_RESULT_FIXED;
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| 		dev->eccFixed++;
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| 		break;
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| 
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| 	case -EBADMSG:
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| 		/* MTD's ECC could not fix the data */
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| 		dev->eccUnfixed++;
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| 		/* fall into... */
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| 	default:
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| 		rettags(etags, YAFFS_ECC_RESULT_UNFIXED, 0);
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| 		etags->blockBad = (mtd->block_isbad)(mtd, addr);
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| 		return YAFFS_FAIL;
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| 	}
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| 
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| 	/* Check for a blank/erased chunk.
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| 	 */
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| 	if (yaffs_CheckFF((__u8 *)&pt1, 8)) {
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| 		/* when blank, upper layers want eccResult to be <= NO_ERROR */
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| 		return rettags(etags, YAFFS_ECC_RESULT_NO_ERROR, YAFFS_OK);
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| 	}
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| 
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| #ifndef CONFIG_YAFFS_9BYTE_TAGS
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| 	/* Read deleted status (bit) then return it to it's non-deleted
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| 	 * state before performing tags mini-ECC check. pt1.deleted is
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| 	 * inverted.
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| 	 */
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| 	deleted = !pt1.deleted;
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| 	pt1.deleted = 1;
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| #else
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| 	(void) deleted; /* not used */
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| #endif
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| 
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| 	/* Check the packed tags mini-ECC and correct if necessary/possible.
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| 	 */
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| 	retval = yaffs_CheckECCOnTags((yaffs_Tags *)&pt1);
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| 	switch (retval) {
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| 	case 0:
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| 		/* no tags error, use MTD result */
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| 		break;
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| 	case 1:
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| 		/* recovered tags-ECC error */
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| 		dev->tagsEccFixed++;
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| 		eccres = YAFFS_ECC_RESULT_FIXED;
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| 		break;
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| 	default:
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| 		/* unrecovered tags-ECC error */
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| 		dev->tagsEccUnfixed++;
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| 		return rettags(etags, YAFFS_ECC_RESULT_UNFIXED, YAFFS_FAIL);
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| 	}
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| 
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| 	/* Unpack the tags to extended form and set ECC result.
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| 	 * [set shouldBeFF just to keep yaffs_UnpackTags1 happy]
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| 	 */
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| 	pt1.shouldBeFF = 0xFFFFFFFF;
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| 	yaffs_UnpackTags1(etags, &pt1);
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| 	etags->eccResult = eccres;
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| 
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| 	/* Set deleted state.
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| 	 */
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| #ifndef CONFIG_YAFFS_9BYTE_TAGS
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| 	etags->chunkDeleted = deleted;
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| #else
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| 	etags->chunkDeleted = (yaffs_CountBits(((__u8 *)&pt1)[8]) < 7);
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| #endif
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| 	return YAFFS_OK;
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| }
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| 
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| /* Mark a block bad.
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|  *
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|  * This is a persistant state.
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|  * Use of this function should be rare.
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|  *
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|  * Returns YAFFS_OK or YAFFS_FAIL.
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|  */
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| int nandmtd1_MarkNANDBlockBad(struct yaffs_DeviceStruct *dev, int blockNo)
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| {
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| 	struct mtd_info * mtd = dev->genericDevice;
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| 	int blocksize = dev->nChunksPerBlock * dev->nDataBytesPerChunk;
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| 	int retval;
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| 
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| 	yaffs_trace(YAFFS_TRACE_BAD_BLOCKS, "marking block %d bad", blockNo);
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| 
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| 	retval = mtd->block_markbad(mtd, (loff_t)blocksize * blockNo);
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| 	return (retval) ? YAFFS_FAIL : YAFFS_OK;
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| }
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| 
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| /* Check any MTD prerequists.
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|  *
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|  * Returns YAFFS_OK or YAFFS_FAIL.
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|  */
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| static int nandmtd1_TestPrerequists(struct mtd_info * mtd)
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| {
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| 	/* 2.6.18 has mtd->ecclayout->oobavail */
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| 	/* 2.6.21 has mtd->ecclayout->oobavail and mtd->oobavail */
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| 	int oobavail = mtd->ecclayout->oobavail;
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| 
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| 	if (oobavail < YTAG1_SIZE) {
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| 		yaffs_trace(YAFFS_TRACE_ERROR,
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| 			"mtd device has only %d bytes for tags, need %d",
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| 			oobavail, YTAG1_SIZE);
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| 		return YAFFS_FAIL;
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| 	}
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| 	return YAFFS_OK;
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| }
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| 
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| /* Query for the current state of a specific block.
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|  *
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|  * Examine the tags of the first chunk of the block and return the state:
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|  *  - YAFFS_BLOCK_STATE_DEAD, the block is marked bad
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|  *  - YAFFS_BLOCK_STATE_NEEDS_SCANNING, the block is in use
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|  *  - YAFFS_BLOCK_STATE_EMPTY, the block is clean
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|  *
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|  * Always returns YAFFS_OK.
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|  */
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| int nandmtd1_QueryNANDBlock(struct yaffs_DeviceStruct *dev, int blockNo,
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| 	yaffs_BlockState * pState, int *pSequenceNumber)
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| {
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| 	struct mtd_info * mtd = dev->genericDevice;
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| 	int chunkNo = blockNo * dev->nChunksPerBlock;
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| 	yaffs_ExtendedTags etags;
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| 	int state = YAFFS_BLOCK_STATE_DEAD;
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| 	int seqnum = 0;
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| 	int retval;
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| 
 | |
| 	/* We don't yet have a good place to test for MTD config prerequists.
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| 	 * Do it here as we are called during the initial scan.
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| 	 */
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| 	if (nandmtd1_TestPrerequists(mtd) != YAFFS_OK) {
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| 		return YAFFS_FAIL;
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| 	}
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| 
 | |
| 	retval = nandmtd1_ReadChunkWithTagsFromNAND(dev, chunkNo, NULL, &etags);
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| 	if (etags.blockBad) {
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| 		yaffs_trace(YAFFS_TRACE_BAD_BLOCKS,
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| 			"block %d is marked bad", blockNo);
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| 		state = YAFFS_BLOCK_STATE_DEAD;
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| 	}
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| 	else if (etags.chunkUsed) {
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| 		state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
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| 		seqnum = etags.sequenceNumber;
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| 	}
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| 	else {
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| 		state = YAFFS_BLOCK_STATE_EMPTY;
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| 	}
 | |
| 
 | |
| 	*pState = state;
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| 	*pSequenceNumber = seqnum;
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| 
 | |
| 	/* query always succeeds */
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| 	return YAFFS_OK;
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| }
 | |
| 
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| #endif /*KERNEL_VERSION*/
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| 
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| --Boundary-00=_5LbTGmt62YoutxM--
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| 
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| 
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| 
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