From mboxrd@z Thu Jan  1 00:00:00 1970
From: Vipin Kumar <vipin.kumar@st.com>
Date: Fri, 7 Dec 2012 10:08:32 +0530
Subject: [U-Boot] [PATCH] fsmc: Skip BBT scan for bad block management
In-Reply-To: <1354822033.8062.10@snotra>
References: <1354822033.8062.10@snotra>
Message-ID: <50C172C8.3050202@st.com>
List-Id: <u-boot.lists.denx.de>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
To: u-boot@lists.denx.de

On 12/7/2012 12:57 AM, Scott Wood wrote:
> On 12/06/2012 01:21:28 AM, Vipin Kumar wrote:
>> This patch forces to read the bad block marker from location 0 in
>> large page
>> nand devices and location 5 in small page devices.
>>
>> Signed-off-by: Vipin Kumar<vipin.kumar@st.com>
>> Reviewed-by: Shiraz Hashim<shiraz.hashim@st.com>
>> ---
>>   drivers/mtd/nand/fsmc_nand.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/mtd/nand/fsmc_nand.c
>> b/drivers/mtd/nand/fsmc_nand.c
>> index 7a61d88..bce4298 100644
>> --- a/drivers/mtd/nand/fsmc_nand.c
>> +++ b/drivers/mtd/nand/fsmc_nand.c
>> @@ -433,7 +433,7 @@ int fsmc_nand_init(struct nand_chip *nand)
>>   	writel(FSMC_THIZ_1 | FSMC_THOLD_4 | FSMC_TWAIT_6 | FSMC_TSET_0,
>>   			&fsmc_regs_p->attrib);
>>
>> -	nand->options = 0;
>> +	nand->options = NAND_SKIP_BBTSCAN;
>>   #if defined(CONFIG_SYS_FSMC_NAND_16BIT)
>>   	nand->options |= NAND_BUSWIDTH_16;
>>   #endif
>
> I don't think this will change the bad block marker behavior -- just
> whether you use a BBT.  Why do you need this?  Why not
> NAND_USE_FLASH_BBT instead?
>

It's because the BootROM which is fused in the device itself (ie 
non-modifiable) is going to read the bad block markers from the oob area.

Which means that anything written via u-boot is non-readable if it uses 
flash bbt

> -Scott
>