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From: Scott Wood <scottwood@freescale.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [U-Boot, v2, 1/3] am33xx: elm: add support for BCH16_ECC - ELM driver updates
Date: Wed, 13 Nov 2013 18:35:57 -0600	[thread overview]
Message-ID: <20131114003557.GA1514@home.buserror.net> (raw)
In-Reply-To: <1378797908-22567-2-git-send-email-pekon@ti.com>

On Tue, Sep 10, 2013 at 12:55:06PM +0530, pekon gupta wrote:
> With increase in NAND flash densities occurence of bit-flips has increased.
> Thus stronger ECC schemes are required for detecting and correcting multiple
> simultaneous bit-flips in same NAND page. But stronger ECC schemes have large
> ECC syndrome which require more space in OOB/Spare.
> This patch add support for BCH16_ECC:
> (a) BCH16_ECC can correct 16 bit-flips per 512Bytes of data.
> (b) BCH16_ECC generates 26-bytes of ECC syndrome / 512B.
> 
> Due to (b) this scheme can only be used with NAND devices which have enough
> OOB to satisfy following equation:
> OOBsize per page >= 26 * (page-size / 512)
> 
> Signed-off-by: Pekon Gupta <pekon@ti.com>
> 
> ---
> arch/arm/cpu/armv7/am33xx/elm.c        | 95 ++++++++++++++++++++++------------
>  arch/arm/include/asm/arch-am33xx/elm.h | 16 +++---
>  2 files changed, 69 insertions(+), 42 deletions(-)

omap_gpmc.c: In function 'omap_correct_data_bch':
omap_gpmc.c:550:19: error: conversion to incomplete type

It looks like this is fixed in patch 2/3, but this breaks bisectability.

Also, does this code really belong under arch/arm rather than
drivers/mtd/nand?

-Scott

  reply	other threads:[~2013-11-14  0:35 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-10  7:25 [U-Boot] [PATCH v2 0/3] mtd: nand: omap: add support for BCH16_ECC Pekon Gupta
2013-09-10  7:25 ` [U-Boot] [PATCH v2 1/3] am33xx: elm: add support for BCH16_ECC - ELM driver updates Pekon Gupta
2013-11-14  0:35   ` Scott Wood [this message]
2013-09-10  7:25 ` [U-Boot] [PATCH v2 2/3] mtd: nand: omap: add support for BCH16_ECC - NAND " Pekon Gupta
2013-11-14  0:40   ` [U-Boot] [U-Boot, v2, " Scott Wood
2013-11-19 13:21     ` Gupta, Pekon
2013-11-19 18:26       ` Scott Wood
2013-11-19 23:50       ` Scott Wood
2013-09-10  7:25 ` [U-Boot] [PATCH v2 3/3] am335x: update README for BCH16 Pekon Gupta

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