Re: mtd/fs/jffs2 erase.c,1.84,1.85 roll back

["Artem B. Bityutskiy" <dedekind@yandex.ru>]

Jörn Engel wrote:
> On Fri, 23 September 2005 17:22:53 +0200, Anders Grafstrom wrote:
> 
>>jffs2 makes a second try if a failed erase is reported by the mtd 
>>driver. But only for NAND (in jffs2_write_nand_badblock()). What I'm 
>>after is a retry for NOR as well. But I wrote the patch so it would 
>>retry for other cases of failure too.
> 
> Is a retry really an improvement?  When a block cannot be properly
> erased on the first try, I would not trust it anymore.  Instead of a
> retry, I'd rather mark it as a bad block and not touch it again.

 From the other hand, why not to retry? Does it hurt? Is this in the 
critical code-path? Deity knows what happend to the hardware/driver, may 
be there was a short magnetical disturbance and that was the reason why 
the block was not erased. May be one of the lines/cirquits outside of 
the flash was affected but the block is really erasable. Actually, after 
I've read the paper that *you* pointed 
(http://www.cs.wisc.edu/adsl/Publications/iron-sosp05.pdf), I'm rather 
positive about the idea of retrying. The articlae is about HDDs, but IMO 
is also acceptable flash devices in this respect.

-- 
Best Regards,
Artem B. Bityuckiy,
St.-Petersburg, Russia.