[U-Boot] [PATCH] ADS5121 NAND driver

[John Rigby <jrigby@freescale.com>]

Wolfgang Denk wrote:
> Dear John Rigby,
>
> In message <1225313050-31063-1-git-send-email-jrigby@freescale.com> you wrote:
>   
>> ADS5121 rev4 / MPC5121e rev2 only
>>
>> Only tested with:
>>     2K page size
>>     8 bit device width
>>
>> This controller treats 2K pages as 4 512 byte pages
>> and the hw ecc is over the combined 512 byte main
>> area and the first 7 bytes of the spare area.
>>
>> The hw ecc is stored in the last 9 bytes of the
>> spare area.
>>
>> This all means the the spare area can not be written
>> separately from the main.  This means unmodified JFFS2
>> will not work.
>>     
>
> Hm... then what exactly is this good for? If we cannot  use  it  with
> the normal Linux code I see little use cases for such a driver?
>   
We have gone over this before offline.  It works great for UBIFS.  It 
also works with JFFS2 if you teach JFFS2 to leave the OOB area alone, 
though there have been reports that there are still issues.

My 5121 linux tree has the two patches necessary for JFFS2 to work, but 
I would recommend using UBIFS.

It is useful in u-boot because you may want to use u-boot to write a 
UBIFS image to NAND.
> Best regards,
>
> Wolfgang Denk
>
>