I'm seeing quite a few failed erases on my system using a Micro 
29F4G08AAC flash part.  This results in the bad block count growing 
quite quickly.  However a scrub and rescan shows only the original 
blocks marked bad out of manufacturing are actually bad.  Changing the 
yaffs code to retry (just once) an erase that fails, always seems to 
show the second erase succeeding (although I've only seen a handful of 
erase failures since trying the change).  I've seen some discussion that 
perhaps the bad-block detection algorithm is overly aggressive at 
marking blocks bad, so I'm wondering if it's safe to retry the erase and 
consider everything good if the second erase succeeds?

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Ben Gamsa       ben@somanetworks.com
SOMA Networks   312 Adelaide St. W. Suite 600 Toronto, Ontario, M5V1R2