From: Scott Wood <scottwood@freescale.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] driver/mtd:IFC NAND:Initialise internal SRAM before any write
Date: Thu, 15 Nov 2012 17:54:28 -0600 [thread overview]
Message-ID: <20121115235428.GA20031@buserror.net> (raw)
In-Reply-To: <1347524765-19174-1-git-send-email-prabhakar@freescale.com>
On Wed, Sep 12, 2012 at 10:26:05PM -0000, Prabhakar Kushwaha wrote:
> IFC-1.1.0 uses 28nm techenology for SRAM. This tech has known limitaion for
> SRAM i.e. "byte select" is not supported. Hence Read Modify Write is
> implemented in IFC for any "system side write" into sram buffer. Reading an
> uninitialized memory results in ECC Error from sram wrapper.
>
> Hence we must initialize/prefill SRAM buffer by any data before writing
> anything in SRAM from system side. To initialize SRAM user can use "READID"
> NAND command with read bytes equal to SRAM size. It will be a one time
> activity post boot
>
> Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
>
> ---
> Based upon git://git.denx.de/u-boot.git (branch master)
>
> This patchs depends upon following patch
> http://patchwork.ozlabs.org/patch/178332/
>
> drivers/mtd/nand/fsl_ifc_nand.c | 62 ++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 61 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mtd/nand/fsl_ifc_nand.c b/drivers/mtd/nand/fsl_ifc_nand.c
> index a518526..140fdc7 100644
> --- a/drivers/mtd/nand/fsl_ifc_nand.c
> +++ b/drivers/mtd/nand/fsl_ifc_nand.c
> @@ -30,6 +30,7 @@
> #include <asm/errno.h>
> #include <asm/fsl_ifc.h>
>
> +#define FSL_IFC_V1_1_0 0x01010000
> #define MAX_BANKS 4
> #define ERR_BYTE 0xFF /* Value returned for read bytes
> when read failed */
> @@ -738,11 +739,66 @@ static void fsl_ifc_select_chip(struct mtd_info *mtd, int chip)
> {
> }
>
> +static void fsl_ifc_sram_init()
fsl_ifc_nand.c:742:13: warning: function declaration isn't a prototype
Fixed and applied to u-boot-nand-flash
-Scott
prev parent reply other threads:[~2012-11-15 23:54 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-13 8:26 [U-Boot] [PATCH] driver/mtd:IFC NAND:Initialise internal SRAM before any write Prabhakar Kushwaha
2012-11-15 23:54 ` Scott Wood [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20121115235428.GA20031@buserror.net \
--to=scottwood@freescale.com \
--cc=u-boot@lists.denx.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox