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Date: Tue, 16 Sep 2014 11:43:12 +0300
From: Roger Quadros <rogerq@ti.com>
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To: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>, Brian Norris
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Subject: Re: [PATCH v3 1/3] nand: omap2: Add support for flash-based bad block
 table
References: <1410447730-16087-1-git-send-email-ezequiel@vanguardiasur.com.ar>
 <1410447730-16087-2-git-send-email-ezequiel@vanguardiasur.com.ar>
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On 09/11/2014 06:02 PM, Ezequiel Garcia wrote:
> This commit adds a new platform-data boolean property that enables use
> of a flash-based bad block table. This can also be enabled by setting
> the 'nand-on-flash-bbt' devicetree property.
> 
> If the flash BBT is not enabled, the driver falls back to use OOB
> bad block markers only, as before. If the flash BBT is enabled the
> kernel will keep track of bad blocks using a BBT, in addition to
> the OOB markers.
> 
> As explained by Brian Norris the reasons for using a BBT are:
> 
> ""
> The primary reason would be that NAND datasheets specify it these days.
> A better argument is that nobody guarantees that you can write a
> bad block marker to a worn out block; you may just get program failures.
> 
> This has been acknowledged by several developers over the last several
> years.
> 
> Additionally, you get a boot-time performance improvement if you only
> have to read a few pages, instead of a page or two from every block on
> the flash.
> ""
> 
> Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>

Acked-by: Roger Quadros <rogerq@ti.com>

cheers,
-roger