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

[Scott Wood <scottwood@freescale.com>]

On 08/18/2011 12:00 PM, Matthieu CASTET wrote:
> b35362@freescale.com a =E9crit :
>> From: Liu Shuo <b35362@freescale.com>
>>
>> Freescale FCM controller has a 2K size limitation of buffer RAM. In or=
der
>> 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 cas=
e,
>> 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 in=
dex
>> in fsl_elbc driver. We can issue any column address by UA instruction =
of
>> elbc controller.
>>
> Why do you need to do that ?
>=20
> 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