From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.nokia.com ([192.100.122.233] helo=mgw-mx06.nokia.com) by bombadil.infradead.org with esmtps (Exim 4.69 #1 (Red Hat Linux)) id 1O7MKc-0003Pr-SA for linux-mtd@lists.infradead.org; Thu, 29 Apr 2010 05:30:41 +0000 Subject: Re: UBI Errors on DaVinci OMAP L-138/DA850 From: Artem Bityutskiy To: Caglar Akyuz In-Reply-To: <201004210115.18664.caglarakyuz@gmail.com> References: <201004210115.18664.caglarakyuz@gmail.com> Content-Type: text/plain; charset="UTF-8" Date: Thu, 29 Apr 2010 08:25:41 +0300 Message-ID: <1272518741.7750.65.camel@localhost> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Cc: Kevin Hilman , David Brownell , linux-mtd@lists.infradead.org Reply-To: dedekind1@gmail.com List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 2010-04-21 at 01:15 +0300, Caglar Akyuz wrote: > Hello, > > Today I made my first attempt to try ubifs on a DaVinci processor, OMAP > L-138 or DA850 specifically. My board has a Micron SLC 128 MiB NAND chip with > part number MT29F1G08ABCHC(chip id is 0xa1) > > I formatted and flashed my partition with commands: > > $ubiformat /dev/mtd4 > $ubiformat /dev/mtd4 -f rootfs.ubi > > Then I tried to attach it with: > > $ubiattach /dev/ubi_ctrl -m 4 > > However, I hit the FAQ entry at [1], namely driver returning -EBADMSG. Then I > tried to mount an empty flash with following commands in case my image has > something wrong: > > $ubiformat /dev/mtd4 > $ubiattach /dev/ubi_ctrl -m 4 > $ubimkvol /dev/ubi0 -N filesytem -s 100MiB > $mount -t ubifs /dev/ubi0_0 /mnt/cf > > But this resulted the same error message when I read/write something to/from the > flash. (To be honest I do not remember if the error was due to read, write or remount) > > Then I tried formating and attaching my partition with '-s 2048' and -O '2048' > parameters respectively and -EBADMSG error went away. So I patched > nand_ids.c to add 'NAND_NO_SUBPAGE_WRITE' option to my NAND flash > (patch is attached) and after this operation I was able to use ubifs as expected > on my board.(Of course re-building my ubi image with new nand parameters) > > I wonder: > > * if this modification has any side effects? Probably sub-pages are not supported with this change? > * Is this error due to my NAND flash or DaVinci driver is doing something wrong? > Unfortunately, Micron datasheet is not publically available and I cannot check if it > is supporting 512 KiB sub-page operations or not. Most probably the flash does support sub-pages because of HW ECC support. I do not know DaVinchi platform at all, but I guess what you need to do is to set NAND_NO_SUBPAGE_WRITE in chip options in your platform data. But it is better to talk to DaVinchi guys (CCed some). -- Best Regards, Artem Bityutskiy (Артём Битюцкий)