data loss on jffs2 filesystem on dataflash
pm at mw-itcon.de
Thu Sep 22 10:59:29 EDT 2005
Andrew Victor wrote:
>>>Problem is here, how does the user get the information about the erase
>>>size used by jffs2?
>>He detects that the flash is DataFlash (mtd->type == MTD_DATAFLASH).
>>Afterwards he knows, that
>>1. mtd->erasesize is the size of DataFlash block
>>2. mtd->oobblock is the size of DataFlash page
> No. You can't change mtd->erasesize.
> There are other existing applications that access the raw MTD layer and
> want the real erasesize.
I agree. The erase size reported to the mtd layer should be always the
physical erase size (528/1056).
>>Sorry, didn't get it. I mean, MTD provide information about both
>>DataFlash block size and DataFlash page size. That's obvious.
> This magic minimum block size could always be calculated in JFFS2 (in
> jffs2_dataflash_setup). It is a JFFS2-specific value.
> Just calculate an 'N' where:
> (N * mtd->erasesize) >= jffs2_minimum_block_size
> (mtd->size % (N * mtd->erasesize)) == 0
That would possible.
Set jffs2->wbuf_size to erasesize and calculate the jffs2->sector size
as you outlined...
Menzebach und Wolff IT-Consulting GbR
Phone +49 751 355 387 1
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