Subject: Re: [PATCH v3] mtd/nand : workaround for Freescale FCM to support large-page Nand chip

From: Scott Wood <[email-masked]>
Date: Thu, 18 Aug 2011 13:24:38 -0500

On 08/18/2011 12:00 PM, Matthieu CASTET wrote:
> [email-masked] a écrit :
>> From: Liu Shuo <[email-masked]>
>>
>> Freescale FCM controller has a 2K size limitation of buffer RAM. In order
>> to support the Nand flash chip whose page size is larger than 2K bytes,
>> we divide a page into multi-2K pages for MTD layer driver. In that case,
>> we force to set the page size to 2K bytes. We convert the page address of
>> MTD layer driver to a real page address in flash chips and a column index
>> in fsl_elbc driver. We can issue any column address by UA instruction of
>> elbc controller.
>>
> Why do you need to do that ?
> 
> When mtd send you a 4k page, why can't you write it by 2*2k pages write ?

That would be more complicated given the statefulness of the interface,
for no real benefit.

> Even better send the first 2K and then if your controller allow it send the
> remaining 2K without command/address phase.

IIRC Shuo tried this first and couldn't make it work.

-Scott