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

From: Artem Bityutskiy <[email-masked]>
Date: Mon, 22 Aug 2011 13:53:08 +0300

On Thu, 2011-08-18 at 10:33 +0800, [email-masked] wrote:
> 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.
> 
> NOTE: Due to there is a limitation of 'Number of Partial Program Cycles in
> the Same Page (NOP)', the flash chip which is supported by this workaround 
> have to meet below conditions.
> 	1. page size is not greater than 4KB 
> 	2.	1) if main area and spare area have independent NOPs:
> 			  main  area NOP    :    >=3
> 			  spare area NOP    :    >=2
> 		2) if main area and spare area have a common NOP: 
> 			  NOP               :    >=4

Could you please also add this kind of info to the driver code comments?

Does it also make sense to print a message if you do the emulation,
like:

	pr_info("attention! emulating 2KiB NAND pages!");

-- 
Best Regards,
Artem Bityutskiy