Re: Fw: corrupt my NAND flash device

["Jörn Engel" <joern@wohnheim.fh-wedel.de>]

On Thu, 24 April 2003 11:25:43 -0700, Alex Samoutin wrote:
> 
> It is nothing wrong with JFFS2 itself. It was a low level problem.  For
> example we have empty flash with 100 erase blocks. We wrote File1 and
> occupied blocks 0-39. Then we deleted this file and start writing File2.
> This new file will be written to blocks 40-79. And now we have two processes
> working.. Process one (GC) is erasing block 0-39, process 2 is writing new
> file to blocks 40-79. Both of them are working at the same time (at least in
> case of JFFS2). I sow it. From blocks point of view all Ok. One set of
> blocks is erasing and absolutely different set of block is writing. But we
> have only one NAND chip. When we want to write something to NAND we have to
> send writing command, then provide some command parameters (like address)
> and then send data itself. And if locking mechanism doesn't work properly we
> can get situation when , for example, one process send command to write and
> then second process start sending something to chip which will be
> interpreted as address for writing but this address will be incorrect, of
> cause. As I mentioned NAND driver (nand.c) has lock mechanism to prevent
> this situation. But it doesn't work in my case. I don't know why - the code
> look Ok. A added some additional locks and it solved this problem.

Ah, sorry for me misinterpreting you original post. I thought, you had
found a problem in yaffs.

Do you have a patch for this? Even if it is ugly and slow, correct
code is better than broken one.

Jörn

-- 
But this is not to say that the main benefit of Linux and other GPL
software is lower-cost. Control is the main benefit--cost is secondary.
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