NAND ECC Issues (summary)

Andrew Foster

Other Parts Discussed in Thread: AM1705

I've noticed a reoccurring theme across several of the TI platform forums. It seems that a lot of users have battled various issues with ECC and memory devices. My goal for this post is to start a discussion with the E2E community about some of the problems they have faced with ECC on their platform (and hopefully there solution.) I think it would aid the E2E community as a whole if we had a catch-all for those trying to debug/develop solutions to their ECC issues on their target.

I'd like to propose a simple format for listing your experiences. I haven't put a lot of thought into a format that will totally encapsulate everyone's application so if anyone has a better idea, please post. My only firm suggestion is one issue per post. Also, please define as a minimum, your

TARGET:

MEMORY INTERFACE:

MEMORY DEVICE:

ISSUE:

DESCRIPTION:

with "SOLUTION: " Being optional.

Thanks,

Andrew

over 14 years ago

0 Andrew Foster over 14 years ago

Intellectual 450 points

TARGET: AM1705

MEMORY INTERFACE: EMIFA 8-Bit

MEMORY DEVICE: NAND Micron 4Gb x 8-bit (MT29F4G08ABADAWP)

ISSUE: BBT Descriptors in u-Boot don't match Linux definitions.

DESCRIPTION: Discrepancies between the BBT main and mirror descriptors don't match between u-Boot and Linux. This causes BBT corruption and various other memory related issues.

SOLUTION:

My fix for that was in board-da830-evm.c: Basically, to comment(/* ARF */) out the original offsets and add those that matched the values in u-Boot.

static struct nand_bbt_descr da830_evm_nand_bbt_main_descr = {

.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE |

NAND_BBT_WRITE | NAND_BBT_2BIT |

NAND_BBT_VERSION | NAND_BBT_PERCHIP,

/* ARF these should match u-boot .offs = 2,

.len = 4,

.veroffs = 16,

.maxblocks = 4,*/

.offs = 8,

.len = 4,

.veroffs = 12,

.maxblocks = 4,

.pattern = da830_evm_nand_bbt_pattern };

static struct nand_bbt_descr da830_evm_nand_bbt_mirror_descr = {

.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE |

NAND_BBT_WRITE | NAND_BBT_2BIT |

NAND_BBT_VERSION | NAND_BBT_PERCHIP,

/* ARF these should match u-boot .offs = 2,

.len = 4,

.veroffs = 16,

.maxblocks = 4,

.pattern = da830_evm_nand_mirror_pattern */

.offs = 8,

.len = 4,

.veroffs = 12,

.maxblocks = 4,

.pattern = da830_evm_nand_mirror_pattern };

0 Andrew Foster over 14 years ago

Intellectual 450 points

TARGET: AM1705

MEMORY INTERFACE: EMIFA 8-Bit

MEMORY DEVICE: NAND Micron 4Gb x 8-bit (MT29F4G08ABADAWP)

ISSUE: HW ECC and writable file system support

DESCRIPTION:

I can't seem to come up with the magic formula for using a JFFS2 file system on my platform. I get various outputs from the mtd device like

mtd->read (some size bytes from some address) returned ECC error:

and also,

JFFS2 error: (937) jffs2_do_read_inode_internal: CRC failed for read_inode of inode 334 at physical location 0x40b4480

Depending on where this happens it can cause kernel crashes.

I'm also getting,

JFFS2 warning: (912)

JFFS2 notice: (940)

and,

Unabled to handle kernel NULL pointer dereference at virtual address 00000001.

All of these messages seem to hover around CRC failures.

SOLUTION: ?

Can anyone definitively answer whether or not HWECC is supported on the Sitara/Davinci platform?

Has anyone figured out the magic configuration for getting u-Boot and the Linux Kernel ECC to play nicely?

I'd like to be able to support filesystem/kernel updates from u-Boot and have support of either UBIFS, JFFS2 or YAFFS under Linux. So far I've failed on all atempts.

Thanks,

Andrew

0 Andrew Foster over 14 years ago in reply to Andrew Foster

Intellectual 450 points

If anyone comes across similar issues with trying to write jffs2 filesystems or ubifs from u-Boot, I've had success working with the latest 2011.06 u-Boot repository patched with

Ben Gardiner's changes to support write.trimffs.

His check-in dates are from 2011-07-01.

Andrew

Processors

Processors forum

NAND ECC Issues (summary)