I had the same problem you must fix this issue in your mtd configuration.<br>go to drivers/mtd/nand/nand_base.c Edit the lines below with correct settings it is related to oobdata. In our nand flash some bytes in spare area is used to determine whether it is a bad block. it is in my case byte 0 byte 1 and byte 5 shows that my block is bad if they dont contain FF. so you must read the manual and change the .oobfree area to a correct place  
<br><br>/*<br><br>static struct nand_oobinfo nand_oob_64 = {<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; .useecc = MTD_NANDECC_AUTOPLACE,<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; .eccbytes = 24,<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; .eccpos = {<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 40, 41, 42, 43, 44, 45, 46, 47,<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 48, 49, 50, 51, 52, 53, 54, 55,
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 56, 57, 58, 59, 60, 61, 62, 63},<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; .oobfree = { {2, 38} }<br>};<br>*/<br><br>static struct nand_oobinfo nand_oob_64 = {<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; .useecc = MTD_NANDECC_AUTOPLACE,<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; .eccbytes = 24,<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; .eccpos = {<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 40, 41, 42, 43, 44, 45, 46, 47,<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 48, 49, 50, 51, 52, 53, 54, 55,<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 56, 57, 58, 59, 60, 61, 62, 63<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; },<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; .oobfree = { {6, 34} }<br>
};<br><br><br><br><br><div class="gmail_quote">On Jan 24, 2008 12:05 PM, Thomas Scariah &lt;<a href="mailto:thomas.scaria@gdatech.co.in">thomas.scaria@gdatech.co.in</a>&gt; wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">






<div bgcolor="#ffffff">
<div>
<div>Hi ....</div>
<div>&nbsp;</div>
<div>I am using a NAND flash of 2K page size. when I go through mailing list I 
am able to know that some other users also faced the same issue.I&#39;m mounting 
using following command after I have enabled following configuration in 
defconfig.</div>
<div>&nbsp;</div>
<div>CONFIG_YAFFS_FS=y<br>CONFIG_YAFFS_YAFFS1=y<br>CONFIG_YAFFS_9BYTE_TAGS=y<br>CONFIG_YAFFS_YAFFS2=y<br>CONFIG_YAFFS_AUTO_YAFFS2=y<br>CONFIG_YAFFS_DISABLE_LAZY_LOAD=y<br># 
CONFIG_YAFFS_DISABLE_WIDE_TNODES is not set<br># 
CONFIG_YAFFS_ALWAYS_CHECK_CHUNK_ERASED is not 
set<br>CONFIG_YAFFS_SHORT_NAMES_IN_RAM=y<br></div>
<div>The commands I am using for mounting is</div>
<div>&nbsp;</div>
<div>flash_eraseall /dev/mtd14</div>
<div>nandwrite -a -o /dev/mtd14 dummy.yaffs2</div>
<div>mount -t yaffs2 /dev/mtdblock14 /mnt/nand</div>
<div>&nbsp;</div>
<div>&nbsp;i also tried</div>
<div>flash_eraseall /dev/mtd14</div>
<div>
<div>mount -t yaffs2 /dev/mtdblock14 /mnt/nand</div>
<div>&nbsp;</div>
<div>But after that if I unmount and remount once more time the files I am 
creating will disappear.At the same time a new file will be creating in the 
folder lost+found,as name objXXXX.the content is still there in the nand 
flash.</div>
<div>&nbsp;</div>
<div>I&nbsp;heard that there is some patch available for MTD device to make the 
yaffs2 working.Also I am using another nand of page size 512 bytes, Its working 
fine with yaffs1.</div>
<div>&nbsp;</div>
<div>please help me to cure this problem..</div></div>
<div>&nbsp;</div>
<div>Regards<br>Thomas Scariah<br></div></div></div>
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