Hi Sharath, by default Yaffs will do a write verify and also an erase verify before writing. Check for CONFIG_YAFFS_DISABLE_WRITE_VERIFY and CONFIG_YAFFS_DISABLE_CHUNK_ERASED_CHECK defines on yaffs_guts.c file to see what's happen during such controls. You'll find them in yaffs_WriteNewChunkToNAND function. The Ecc check is done at read time (so also during write verify ;), search for it in yaffs_ReadChunkFromNAND; it can ben enabled/disabled setting dev->useNANDECC option or using the define CONFIG_YAFFS_USE_NANDECC (in this case will work only for the MTD layer). The bad block marking isn't clear for me yet, since I can't find a 'real' block marking procedure (say writing some non-volatile infos somewhere), while it seems that yaffs simply discards chuncks that produce errors and retry with new ones until it can succeed in the requested operation. I hope this info will be usefull. Regards Adamo > -----Original Message----- > From: Skumar [mailto:skumar@mistralsoftware.com] > Sent: venerd 16 aprile 2004 06.52 > To: yaffs > Subject: bad block problem > > > Hi, > i want to know on what condition will yaffs mark a block bad? > my assumption is when it does a page read & compares the ecc > calculated & > the ecc stored in oob > and if it does not match it marks the blcok bad. is this correct > > will yaffs do write verify(ie will it read back the page > after write and > check for ecc)? > > > Regards > sharath > > > > > > Sharath > > > > > > I had exactly that problem a while back till I made sure > that the ecc > > connectivity between yaffs and mtd was working right. > Things like one mtd > > layer being passed an integer indicating which oob style to use and > another > > being passed a pointer into an array of oob defs. Both > versions link fine > of > > course. There is also some potential for confusion with the > yaffs and > smart > > media locations too. > > > > > > If it is *nearly* right then reads often seem ok but the > block is marked > > as bad and when the data is moved a bad block marker stops > reuse of the > > block. Erasing the bad block marks is bad as this also removes the > > manufacturer bad block marks and the mtd filters this out. > For dev work I > > stomp on this filter and accept any bad consequences. > > > > > > See http://62.49.201.250/balloon/ for sample linux source > trees with > yaffs > > integration - new 2.4.25-vrs2-tcl1 added recently. > > > > > > Nick > > > > > > ----- Original Message ----- > > > From: "Skumar" > > > To: "yaffs" > > > Sent: Thursday, March 25, 2004 5:54 AM > > > Subject: bad block problem > > > > > > > > > > hin > > > > i am working on s3c2410 processor using yaffs above mtd > on NAND flash. > > > > i am facing problem that sometimes the yaffs is marking > all the blocks > > as > > > > bad & the yaffs partition becomes unusable. > > > > i want to know if someone has faced this problem before. > > > > i want to know whether to debug yaffs or mtd? > > > > > > > > Regards > > > > sharath > > > > > > > > > > > > > > > > > > > > -------------------------------------------------------------- > ------------ > > ------------- > > > > This mailing list is hosted by Toby Churchill open software > > (www.toby-churchill.org). > > > > If mailing list membership is no longer wanted you can > remove yourself > > from the list by > > > > sending an email to yaffs-request@toby-churchill.org > with the text > > "unsubscribe" > > > > (without the quotes) as the subject. > > > > > > > > > > > > ?+&j)bz > > > bج?<-yN?r-S^z{0ho/??)eSTSx%Sfzfޮ > b+'Z'j{^w > > *.qzj/{*.ǥ}s^-+-o+اTOs}z?nb-_ > > "azױr>{Shazjaz>- > > > > > > > > > > > -------------------------------------------------------------- > ------------------------- > This mailing list is hosted by Toby Churchill open software (www.toby-churchill.org). If mailing list membership is no longer wanted you can remove yourself from the list by sending an email to yaffs-request@toby-churchill.org with the text "unsubscribe" (without the quotes) as the subject. --------------------------------------------------------------------------------------- This mailing list is hosted by Toby Churchill open software (www.toby-churchill.org). If mailing list membership is no longer wanted you can remove yourself from the list by sending an email to yaffs-request@toby-churchill.org with the text "unsubscribe" (without the quotes) as the subject.