From mboxrd@z Thu Jan  1 00:00:00 1970
From: pieterg@gmx.com (pieterg)
Date: Wed, 22 Sep 2010 19:12:24 +0200
Subject: pxa3xx_nand issues
Message-ID: <201009221912.24905.pieterg@gmx.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

In my search for the cause of the huge number of single/double bit errors 
I'm experiencing on colibri pxa320/310 devices, I've come across this 
commit

http://git.kernel.org/?p=linux/kernel/git/ycmiao/pxa-linux-2.6.git;a=commit;h=7f9938d0fd6c778bd0ce296a3e3b50266de2b892

According to the commitlog, it attempts to work around an issue regarding 
non-page-aligned reads.
The workaround seems to force page-aligned access, by dropping the offset 
within the page (column address bytes).
However, in my setup (with a jffs2 filesystem on nand), non-page-aligned 
reads never occur, but non-page-aligned writes occur very frequently. 
(during the jffs2 gc).
These are also affected by this commit, while the commitlog does not state 
whether or not the same issue would occur for the program command, and in 
that case, whether or not the same workaround would apply.

I've tried to revert the commit, but unfortunately this doesn't reduce the 
huge number of single/double bit errors (and jffs2 crc errors as a result) 
I'm getting.

But having these non-aligned writes during GC, would that indicate a problem 
with my jffs2 image parameters perhaps?
(though I cannot imagine this could actually cause double bit errors)

Rgds, Pieter