lkml.org 
[lkml]   [2021]   [May]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 0/2] Fix double counting of S/W ECC engines' ECC stat
Hi YouChing,

ycllin@mxic.com.tw wrote on Thu, 13 May 2021 10:11:02 +0800:

> > "Miquel Raynal" <miquel.raynal@bootlin.com>
> <deleted>
> >
> > Good catch!
> >
> > However I don't think the current fix is valid because these engines
> > are meant to be used by the raw NAND core as well, I propose something
> > like the below, can you please tell me if it works as expected? (not
> > even build tested)
> >
> > Thanks,
> > Miquèl
> >
> >
> <deleted>
>
> Thanks for your work.
>
> I tested the two patches(yours and mine) separately in our environment:
> 1) MXIC NFC(&raw NAND),2) MXIC SPI host(&SPI-NAND) with S/W BCH engine.
> Both patches are valid(using nandtest/nandbiterrs, values of ecc_stats are
> normal).
>
> This seems to be because the function(nand_ecc_sw_bch_finish_io_req()
> in ecc-sw-bch.c) that would increase the ecc_stats counter is not used
> in the raw NAND world. Am I misunderstanding or is it platform dependency?

I don't think it can be called a platform dependency, it's more like
legacy from the raw NAND world which makes the use of the generic ECC
framework hard and thus is limited to a given set of functions.

> BTW, I think your modification should be more in line with the design
> spirit
> of generic ECC engine framework.

Yes, ideally raw NAND should fully comply to this framework but this
would require a hundred days of work and dozens of available boards to
test. During the past 20 years people assumed NAND controller and ECC
engine were a single entity which makes the use of the generic ECC
framework hard to implemented in the raw NAND. So I decided not to put
all my energy there in order to first get this framework available to
SPI-NAND devices.

Thanks,
Miquèl

\
 
 \ /
  Last update: 2021-05-13 08:46    [W:0.040 / U:0.256 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site