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Subject: Re: UBI memory usage on large page nand
From: Artem Bityutskiy <dedekind1@gmail.com>
To: Nicholas <ciliwung36@gmail.com>
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Date: Sun, 17 Apr 2011 12:16:14 +0300
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On Sun, 2011-04-17 at 17:03 +0800, Nicholas wrote:
> Dear Artem,
> 
> Thanks for the advices. I'll try start for UBI first.
> 
> Reducing peb_buf would mean i need to modify the ubi IO for read/write.
> As i know, ubi did an erase for a whole block before start writing,
> 
> Please correct me if i've written in a wrong way.

Yes, when you investigate the code, you'll even find that if extra self
checks are enabled, UBI will verify that the area it writes to contains
only 0xFFs - it will read the area, compare with 0xFFs, and if all bytes
are 0xFFs it will proceed, otherwise it will shout loudly. See:

ubi_io_write() - all writes go through this function, and
ubi_dbg_check_all_ff - does the verification I talked about, but only in
debugging mode, because it is too costly to do it in production mode.

-- 
Best Regards,
Artem Bityutskiy (Битюцкий Артём)