Re: Missing support for ECC_SOFT_BCH in fsl-elbc-nand

[Scott Wood <scottwood@freescale.com>]

On Mon, 2015-04-13 at 23:56 +0200, Tomas Hlavacek wrote:
> Hi!
> 
> On Monday, April 13, 2015 9:12:33 PM CEST, Scott Wood wrote:
> > On Mon, 2015-04-13 at 00:30 +0200, Tomas Hlavacek wrote:
> >> 1) How to disable HW ECC?
> >> 
> >> What I have done is this:
> >> 
> >> diff --git a/drivers/mtd/nand/fsl_elbc_nand.c  ...
> >
> > You shouldn't be setting BR_DECC if you don't want to use HW ECC, so
> > this ifdef doesn't accomplish anything.
> >
> > Also, while a compile-time hack may be suitable for your own use, to get
> > a mergable patch it should be a runtime decision.  You should be able to
> > read at runtime the level of ECC that the flash requires.
> 
> How? Could you please point me to some starting point what to read in order 
> to implement it?

The information should be in the chip's identification bytes, either via
ONFI or a manufacturer-specific format.  Or, if that's too complicated,
at least indicate the type of ECC to be used in the device tree.

-Scott