[U-Boot] [RFC 4/5] SPL:Defines function required to env read for IFC & env_nand

[Prabhakar Kushwaha <prabhakar@freescale.com>]

On 09/23/2013 11:49 PM, Scott Wood wrote:
> On Wed, 2013-09-18 at 16:40 +0530, Prabhakar Kushwaha wrote:
>> Thanks Scott for taking time and reviewing the RFC patch.
>>
>> Please find my reply in-lined.
>>
>> On 09/17/2013 05:23 AM, Scott Wood wrote:
>>> On Mon, 2013-09-16 at 21:35 +0530, Prabhakar Kushwaha wrote:
>>>> fsl_ifs_spl.c reads data from NAND and store at a memory location in raw mode.
>>>> It does not used MTD layer.
>>>> To read env variable from NAND MTD layer read/write required.
>>>>
>>>> Hence, add mtd_block_isbad & nand_read_skip_bad function required during
>>>> env variable read.
>>>>
>>>> Also, avoid nand_info during env read for SPL
>>>>
>>>> Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
>>>> ---
>>>>    common/env_nand.c              |    7 ++++---
>>>>    drivers/mtd/nand/Makefile      |    2 +-
>>>>    drivers/mtd/nand/fsl_ifc_spl.c |   22 ++++++++++++++++++++++
>>>>    3 files changed, 27 insertions(+), 4 deletions(-)
>>>>
>>>> diff --git a/common/env_nand.c b/common/env_nand.c
>>>> index 7530962..7a7107f 100644
>>>> --- a/common/env_nand.c
>>>> +++ b/common/env_nand.c
>>>> @@ -246,11 +246,13 @@ int readenv(size_t offset, u_char *buf)
>>>>    	u_char *char_ptr;
>>>>    
>>>>    	blocksize = nand_info[0].erasesize;
>>>> +#ifndef CONFIG_SPL_BUILD
>>>>    	if (!blocksize)
>>>>    		return 1;
>>>> -
>>>>    	len = min(blocksize, CONFIG_ENV_SIZE);
>>>> -
>>>> +#else
>>>> +	len = CONFIG_ENV_SIZE;
>>>> +#endif
>>> Use positive logic (ifdef/else, not ifndef/else).
>> I will fix it.
>>
>>> Are you sure that CONFIG_ENV_SIZE will always be appropriate?  Shouldn't
>>> you use CONFIG_SYS_NAND_BLOCK_SIZE in place of nand_info[0].erasesize?
>> I can use CONFIG_SYS_NAND_BLOCK_SIZE . but i can not use in SPL as its
>> is defined as 128K.
> You can't redefine the block size to suit your needs.  It's a property
> of the hardware.  What difference does it make, as long as
> CONFIG_ENV_SIZE is smaller?
Earlier code was like
  len = min(blocksize, CONFIG_ENV_SIZE) as SPL never defines nand_info. 
So the block size is 0.
causing len = 0.

I am avoiding it by setting  = CONFIG_ENV_SIZE. No redefinition of block 
size.

Regards,
Prabhakar