[U-Boot] [PATCH 6/6] EA20: do not use subpage write for NAND

Stefano Babic
2011-04-22T07:13:34Z

On 04/15/2011 10:29 PM, Scott Wood wrote:

>
> nand_scan() is broken into head and tail functions. In Linux, the driver
> calls these, and can look at the chip info before tail is called. In
> U-boot, common code drives this, and the controller driver is not involved
> -- but it would be good to change this.

Agree, we can do in this way.

>
>>> For example, fsl_elbc_nand.c sets NAND_NO_READRDY and NAND_NO_AUTOINCR.
>>> Before this thread, I didn't realize it they were getting ignored.
>>> Things
>>> work anyway because the former is an optimization, and the latter is getting
>>> forced on after the masking, for some reason -- does autoincr simply not
>>> work? Can we remove the code? :-)
>>
>> Well, the options are simply ignored, I agree about removing them.
>
> I think it can be enabled by the controller driver between head and tail
> (at least on Linux), though I don't see any drivers that do this as far as
> a quick grep shows.

The only point is we need that the controller checks the parameters
after the tail part, as the tail part scans the chip and sets its
options, as the SUBPAGE flag. We could add a pre_adjust() and
post_adjust() functions to be called after the head and tail part of the
nand_scan().

Best regards,
Stefano

--
=====================================================================
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-0 Fax: +49-8142-66989-80 Email: office at denx.de
=====================================================================