using MEMWRITEOOB problem in NAND flash device

using MEMWRITEOOB problem in NAND flash device

[Paul Wong]

 Hi All,
     I want to restore the oob[5] using ioctl(..,MEMWRITEOOB,..) in NAND
 flash device, but it is failure to write anything. Is any protected
 condition in NAND.C?
 
 Thanks.
 
 Paul
 

Re: using MEMWRITEOOB problem in NAND flash device

[Thomas Gleixner]

On Friday 18 April 2003 17:06, Paul Wong wrote:
>  Hi All,
>      I want to restore the oob[5] using ioctl(..,MEMWRITEOOB,..) in NAND
>  flash device, but it is failure to write anything. Is any protected
>  condition in NAND.C?
You _CANNOT_ write a 0 bit to 1 on a FLASH chip. This works the other way 
round. If you want to restore your block, remove the santity check in erase 
function of nand.c.

Last answer to this

-- 
Thomas
________________________________________________________________________
linutronix - competence in embedded & realtime linux
http://www.linutronix.de
mail: tglx@linutronix.de

Re: using MEMWRITEOOB problem in NAND flash device

[Paul Wong]

Thanks. I got it.

Paul
----- Original Message -----
From: "Thomas Gleixner" <tglx@linutronix.de>
To: "Paul Wong" <paul.wong@digitalview.com>;
<linux-mtd@lists.infradead.org>; "yaffs list" <yaffs@toby-churchill.org>
Sent: Saturday, April 19, 2003 12:14 AM
Subject: Re: using MEMWRITEOOB problem in NAND flash device


> On Friday 18 April 2003 17:06, Paul Wong wrote:
> >  Hi All,
> >      I want to restore the oob[5] using ioctl(..,MEMWRITEOOB,..) in NAND
> >  flash device, but it is failure to write anything. Is any protected
> >  condition in NAND.C?
> You _CANNOT_ write a 0 bit to 1 on a FLASH chip. This works the other way
> round. If you want to restore your block, remove the santity check in
erase
> function of nand.c.
>
> Last answer to this
>
> --
> Thomas
> ________________________________________________________________________
> linutronix - competence in embedded & realtime linux
> http://www.linutronix.de
> mail: tglx@linutronix.de
>
>
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