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Date: Tue, 20 Sep 2005 17:01:42 +0200
From: Peter Menzebach <pm-mtd@mw-itcon.de>
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Cc: "Artem B. Bityutskiy" <dedekind@yandex.ru>,
	Linux MTD <linux-mtd@lists.infradead.org>
Subject: Re: data  loss on jffs2 filesystem on dataflash
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Artem B. Bityutskiy wrote:
> On Tue, 2005-09-20 at 15:38 +0200, Peter Menzebach wrote:

...
> 
> But In your logs, I saw that you have *write buffer* size = 8*1056!
> Write buffer size is another thing. It is the minimal flash IO unit.
> JFFS2 assumes that it cannot write 1 byte or 100 bytes, it assumes that
> it can only write 'write buffer size' bytes. And the goal of the write
> buffer is to accumulate many small JFFS2 writes in RAM, and when the
> write buffer becomes full, it is flushed to flash. 
> 
> So, in your case, make write buffer = Data Flash page size = 1056.
> 
How can this reported from the flash device to the mtd layer and then to 
jffs2?
In the code, I see at the moment only, that in the device driver 
mtd_info.erasesize is set, later on in jffs2 I see, that this has become 
the sector_size, which becomes then the wbuf_pagesize.

Is here mtd_info.ooblock to be set?


Best regards
Peter

-- 
Peter Menzebach
Menzebach und Wolff IT-Consulting GbR
Phone +49 751 355 387 1