Setting ECC On DIE at u-boot and NAND_ECC_NONE at kernel

Krunal Patel_11

Hello TI,

We need your quick confirmation that despite we see the following message at AM boot (“NAND_ECC_NONE selected by board driver. This is not recommended !!”) the NAND is configured for ECC ONDIE mode.

The ONDIE mode is configured only at U-Boot stage and afterwards there is no necessity to reconfigure it in kernel.

Also can anyone explain what happens when we select NAND_ECC_NONE from kernel?

Thanks in advance.

Thanks,

Krunal

over 10 years ago

0 Biser Gatchev-XID over 10 years ago

TI__Guru**** 393215 points

Hi Krunal,

What processor and what Linux version is this?

0 Krunal Patel_11 over 10 years ago in reply to Biser Gatchev-XID

Expert 2250 points

Hi Biser,

We are using AM35xx with linux kernel version 2.6.37.

Thanks,
Krunal

0 Biser Gatchev-XID over 10 years ago in reply to Krunal Patel_11

TI__Guru**** 393215 points

I have asked for support on this. Feedback will be posted here.

0 Krunal Patel_11 over 10 years ago in reply to Biser Gatchev-XID

Expert 2250 points

Hello Biser,

Any updates on this?

Thanks,
Krunal

0 Biser Gatchev-XID over 10 years ago in reply to Krunal Patel_11

TI__Guru**** 393215 points

Feedback will be posted here when available.

0 Biser Gatchev-XID over 10 years ago in reply to Biser Gatchev-XID

TI__Guru**** 393215 points

Hi,

Meanwhile I found this document that may be useful to you: http://www.google.bg/url?sa=t&rct=j&q=&esrc=s&source=web&cd=10&cad=rja&uact=8&ved=0CGMQFjAJ&url=http%3A%2F%2Fwww.micron.com%2F~%2Fmedia%2Fdocuments%2Fproducts%2Ftechnical-note%2Fnand-flash%2Ftn2956_ondie_ecc_omap3_linux.pdf&ei=4Nw4VdvoI-efyAPW_YHACQ&usg=AFQjCNEq5FsF8DkUHGh5ya3xLvi3f9u1eQ&bvm=bv.91427555,d.bGQ

0 Krunal Patel_11 over 10 years ago in reply to Biser Gatchev-XID

Expert 2250 points

Hi Biser,

I do have gone through the same document. But this document explains only how to enable OnDie ECC for YAFFS2.

What I am looking for is what happens if we select NAND_ECC_NONE from kernel if we have configured Nand for On Die ECC at Uboot?

Thanks,
Krunal

0 Biser Gatchev-XID over 10 years ago in reply to Krunal Patel_11

TI__Guru**** 393215 points

I think this document describes kernel changes too.

0 Krunal Patel_11 over 10 years ago in reply to Biser Gatchev-XID

Expert 2250 points

Yes it do describes the required kernel changes. But I don't want to reconfigure my nand for OnDie ECC mode from kernel if its done at Uboot.

Please let me know if I am not able to explain my queries and requirement.

Thanks,
Krunal

0 Krunal Patel_11 over 10 years ago in reply to Krunal Patel_11

Expert 2250 points

Also please let me know if the mentioned kernel changes are mandatory?

Thanks,
Krunal

0 Biser Gatchev-XID over 10 years ago in reply to Krunal Patel_11

TI__Guru**** 393215 points

Please check section 3 from the document. There is no reconfiguration of NAND ECC mentioned there. The necessary changes listed are:

Step 1: Disable standard hardware and software ECC (this is on the AM35X side, not on NAND side).

Step 2: Modify the OOB layout to accommodate the new ECC map.

Step 3: Poll for status after READ (required after every READ); check for errors beyond the 4 handled by the on-die ECC. When an error is logged, there is some form of data corruption.

Step 4: Verify that NAND Flash timing requirements are met, with sufficient time to complete the required status check.

Processors

Processors forum

Setting ECC On DIE at u-boot and NAND_ECC_NONE at kernel