[U-Boot] [PATCH 1/1] ppc4xx: add support for alternate format for ndfc

[Feng Kan]

Hi Stefan:
 
There is not a particular board that is stuck on this 213 format. Rather, for sometime u-boot
and linux both had the 213  ordering. Lets say the guy did not have the SMC define turned on,
which mean the ECC would caculate correctly for him. Now, he gets a new U-boot and want 
to update it. He gets to prompt and programs the new u-boot and linux (in 213 ordering).
The new uboot comes up (it doesn't complain since there is no error message), runs to linux,
the new linux expects 123 ordering. Finds ECC error and tries to correct and crash.
 
I submitted this patch to support both ordering that the correction routine contains (123 and 213).
Realistically, you can have any ordering you want (312 321) as long as the correction routine
supports it. It is because of this reason, that the ndfc.c ordering keeps getting changed. I want
the user to lock down the ordering they use. So they don't make the mistake of selecting
SMC define but uses the 213 ordering (which would cause ecc errors). 
 
Cheers,
Feng

________________________________

From: Stefan Roese [mailto:sr at denx.de]
Sent: Mon 2/22/2010 2:52 AM
To: Feng Kan
Cc: u-boot at lists.denx.de
Subject: Re: [U-Boot] [PATCH 1/1] ppc4xx: add support for alternate format for ndfc



Hi Feng,

On Friday 19 February 2010 19:27:24 Feng Kan wrote:
> Agreed the ordering is working now. Previously the ordering is 213 and with
> CONFIG_MTD_NAND_ECC_SMC defined, wrong ECC error bit position was
> calculated. What about the boards that are now stuck on the 213 ordering.

Which boards are stuck with this (incorrect) ordering? Please give an example.

> Also in linux, the ordering is not fixed down as in u-boot.

I thought we had this fixed (or synced) in U-Boot *and* Linux.

> Hmm, perhaps
> that is another approach to the problem. Fix the ordering in linux?

Again, I fail to see the problem here. Please give an example which board is
failing here.

Thanks.

Cheers,
Stefan

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