[PATCH] Towards DiskOnChip support as a NAND driver

Thomas Gleixner tglx at linutronix.de
Wed Jun 16 18:32:09 EDT 2004

On Wednesday 16 June 2004 16:19, Dan Brown wrote:
> Please realize that this needs a lot more testing.  I still haven't gotten
> JFFS2 to run properly with this (though I suspect that may reflect my
> inexperience with JFFS2).  Also, the change to nand.h may break other nand
> drivers (though the fix is trivial).

The nand.h change is fixed in nand_ecc.c

>     - Modifying JFFS2 to use autooob layout?  (Not sure about this)
>     - Modifying flash_eraseall to use autooob layout?  (Should work OK on
> DOC by coincidence)

Yes, flash_eraseall works by coincidence, but I will look into this.

>     - Adding the nand/diskonchip driver into the kernel build system
> instead of the old one

Can you make it optional to use or should we break the code in 
drivers/mtd/devices to enforce the development on Dan's code in 
drivers/mtd/nand ? 

dwmw2 ??

IMHO the current DOC code in drivers/mtd/devices has too many todo's which 
inhibit proper usage. 

They are partly related to the bad block management. The bad block management 
support in the generic nand driver is able to support all types of bad block 
tables found on DOC devices. 

We fixed the HW ecc problems in nand_base.c today. 

It should be not too hard to adjust (I)NFTL to work on the new driver.

Some specialities of the DOC variants which are already working in the old 
drivers should be easily copyied to the new one as Dan has already done for 
his chip.

Another point is the error correction code. I have a generic reed solomon 
library nearly finished which is then usable for all kind of reed solomon 
based hw ecc generators. I don't want to make the old drivers use it and I 
dont wan't to have duplicate code around.

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