[U-Boot] [PATCH v8 0/5] mtd: nand: omap: optimize and clean-up of OMAP NAND driver
matti kaasinen
matti.kaasinen at gmail.com
Thu Nov 7 10:40:58 CET 2013
Pekon,
Please find the nand dumps from oob area below. UBIFS volume created and
edited in Linux.
Linux:
OOB Data: ff ff ff ff ff ff ff ff ff ff ff ff 5c 87 73 23
OOB Data: ae 36 a6 16 fc 81 dd 8e f0 ff ff ff ff ff ff ff
OOB Data: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
OOB Data: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
U-Boot:
OOB:
ff ff ff ff ff ff ff ff
ff ff ff ff 90 df 27 b0
f7 8c db 4c 0e 76 25 7e
a9 ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff
Best regards,
Matti
2013/11/7 matti kaasinen <matti.kaasinen at gmail.com>
> Hi Pekon,
> Thank you for your answers. Please find my answers/comments to your
> questions below.
>
> 2013/11/6 Gupta, Pekon <pekon at ti.com>
>
> Hi Matti and Matthias
>>
>> Sorry I was away from my mailbox so couldn't reply you earlier.
>> I'm still away from my setup and other boards, so cannot replicate
>> the issue below until early next week. But I'll surely do so asap..
>>
>> However, please see my replies below, which might help you someway.
>>
>>
>> > From: matti kaasinen [mailto:matti.kaasinen at gmail.com]
>> > Hi Pekon,
>> > Thanks to Tom Rini's hint I have tried to execute your patch sets
>> > (
>> http://patchwork.ozlabs.org/project/uboot/list/?submitter=17320&state=*)
>> > in order to get Linux and U-Boot working with same NAND flash.
>> > Set-up is pretty much like Mathias has before in this chain.
>> > Latest problem I faced with is that last versions of
>> > 1) "[U-Boot,v8,3/5] mtd: nand: omap: optimize chip->ecc.calculate()
>> for H/W ECC schemes"
>> > and 2) "[U-Boot,v2,2/3] mtd: nand: omap: add support for BCH16_ECC -
>> NAND driver updates"
>> > are not compatible any more. As I told in
>> > https://groups.google.com/forum/#!topic/beagleboard/7ofbE_Rrn_s
>> > versions v5..v7 of 1) could possibly be compatible.
>>
>> There is no change in ECC layout or other functional updates between
>> v7 and v8 of this patch, so if there is any incompatibility then it would
>> be in all versions of the patch..
>>
>
> I did not mean "ECC layout-wisely" incompatible but "patching-wisely"
> incompatible. Patching 2) v2 after 1) v8 stops to errors and it seems that
> with 1) v7 it could (possibly) succeed.
>
> Few questions..
>> (1) Which ECC scheme are you using ?
>>
>
> Now I'm talking Linux 3.8.13 - U-Boot 10.04 combination that I have as
> currently as "working" environment. I have not managed getting above
> patches successfully through.
>
>> - u-boot
>> CONFIG_NAND_OMAP_ECCSCHEME as per doc/README.nand
>> http://lists.denx.de/pipermail/u-boot/2013-October/164646.html
>>
> U-Boot 10.04 does not seem to have such choices and in fact I have not
> selected it.
>
>> - kernel
>> OMAP_ECC_BCH8_CODE_HW
>> OMAP_ECC_BCH8_CODE_HW_DETECTION_SW
>> Or any other..
>>
>
> I believe OMAP_ECC_BCH8_CODE_HW gets selected with following options from
> kernel.
>
> CONFIG_MTD_NAND_OMAP2
> CONFIG_MTD_NAND_OMAP_BCH
> CONFIG_MTD_NAND_OMAP_BCH8
>
> ... and selecting following choice
>
> ti,nand-ecc-opt = "bch8"
>
> in device tree.
>
> With these options boot process reports;
> [ 1.128154] enabling NAND BCH ecc with 8-bit correction
> [ 1.133985] ONFI param page 0 valid
> [ 1.137662] ONFI flash detected
> [ 1.140985] NAND device: Manufacturer ID: 0x2c, Chip ID: 0xda (Micron
> MT29F2G08AAD), 256MiB, page size: 2048, OOB size: 64
>
> First line seems coming from drivers/nand/mtd/omap2.c:omap3_init_bch
> that gets printed in this from only if OMAP_ECC_BCH8_CODE_HW ==
> platform_data.ecc_opt
>
> I printed nand.ecc.layout.eccbytes = 52 ( from from
> drivers/nand/mtd/omap2.c:omap3_init_bch_tail )
> and
> nand.ecc.layout->eccpos[] = 12..63
>
> BTW it seems that similar layout has been defined in u-boot
> arch/arm/include/asm/arch-omap3/omap_gpmc.h
> There is one exception, though: eccbytes have been set 54 instead of 52
> that seems to be in linux (and correct I suppose).
>
>
>>
>>
>> (2) Is the problem related to incorrect read/write access to x16 NAND ?
>>
> No using x8 NAND
>
>> Or
>> Is it incompatibility in ecc.layout ?
>>
> You can check this by dumping raw nand page via 'nand dump' command
>> from both u-boot and kernel.
>>
>>
> I'll try to check this
>
>>
>
> (3) you should not pick BCH16 patch-series
>> - because I have not rebased this patch, and re-tested since other
>> base patch-series on which BCH16 will be build, is still not accepted.
>> - Also BCH16 ecc scheme would work only for
>> NAND device with pagesize=4K and oobsize=224.
>> whereas current beaglebone capes have
>> NAND device with pagesize=2K and oobsize=64, so you can only use
>> BCH8 with current NAND capes (for now)..
>>
> This is perfectly fine with me. This set seems to block patching. I need
> only BCH8 and if this patch set provides only BCH16 functionality and
> nothing else, I need not using it.
>
>>
>>
>
>>
>
>> > > 2013/11/1 Matthias Fuchs <mfuchs at ma-fu.de>
>> > > Hi Pekon,
>> > >
>> > > should I consider the U-Boot and Linux am335x NAND
>> > > implementation to be compatible? So are the ECC schemes
>> > > in a way identical that I can nandwrite a kernel image from
>> > > Linux and "nand read" it from U-Boot? I tested with the 3.8.13
>> > > beaglebone kernel (which is of course not very representative)
>> > > and it does not work. If it should work, do you know it that was
>> > > already the case before your patches and with which Linux kernel?
>>
>> I don't think any earlier kernel versions ever supported beaglebone
>> Its only recently that a major patch-series of NAND driver was
>> accepted and tested on beaglebone.
>> The patches are currently in l2-mtd.git tree which should make into
>> 3.13 kernel, before being in linux-next for sometime.
>> (a) Reference:
>> http://lists.infradead.org/pipermail/linux-mtd/2013-October/049462.html
>>
>> (b) In addition to above series, you might need beaglebone DTS updates
>> which you can refer from below ..
>> http://lists.infradead.org/pipermail/linux-mtd/2013-October/049438.html
>>
>> So, you mean that it should not be possible to access beaglebone (alike)
> board NAND with Linux 3.8.13. However, it seems that I can access it from
> Linux (well, I have done some patching for IO and mux and device tree).
> Problem really is that U-Boot and Linux handle it in different ways so that
> if I create e.g. ubifs volume in Linux, that works quite fine. I can
> rean/write it quite fine. However, if I mount it from U-boot, it get tons
> of ecc error messages and as a result it gets corrupted. After that also
> Linux side prints tons of ecc error messages while acessing it.
>
>>
>> with regards, pekon
>
> Thanks,
> Matti
>
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