Re: [PATCH] Correct corrupted NAND Flash access on KARO TX25 modules

Dear Marek,

>
>Dear Gachet Daniel,
>
>> This short patch correct corrupted data while reading NAND flash 
>> modules on the KARO TX25 module.
>> 
>> The current version of the mxc_nand driver uses the symmetric mode to 
>> access the NAND flash, but the devices populated on the KARO TX25 only 
>> support an asymmetric mode (i.MX25: bit 8  within NAND_FLASH_CONFIG1 
>> register cleared).
>> 
>> Signed-off-by: Daniel Gachet <daniel.gachet <at> hefr.ch>>
>> Cc: Wolfgang Denk <wd <at> denx.de >>
>> 
>> diff -upr drivers/mtd/nand/mxc_nand.c drivers/mtd/nand/mxc_nand.c
>> --- drivers/mtd/nand/mxc_nand.c	2011-12-23 20:25:35.000000000 +0100
>> +++ drivers/mtd/nand/mxc_nand.c	2012-03-30 08:10:13.000000000 +0200
>>  <at>  <at>  -1290,7 +1290,9  <at>  <at>  static void mxc_setup_config1(void)
>>  	uint16_t tmp;
>> 
>>  	tmp = readw(&host->>regs->>nfc_config1);
>> +#ifndef MACH_TYPE_TX25
>>  	tmp |= NFC_ONE_CYCLE;
>> +#endif
>>  	tmp |= NFC_4_8N_ECC;
>>  	writew(tmp, &host->>regs->>nfc_config1);
>>  	if (host->>pagesize_2k)
>> 
>
>Won't it be better to make this more generic rather then adding more machine- specific hacks please?
>
>Best regards,
>Marek Vasut

It's really a good question. 

This modification should probably work on other i.MX25 boards, because it relaxes the timing while
accessing the NAND flash. But unfortunately I haven't other i.MX25 boards on which I can verify this
modification.  Do you have other modules to validate this modification?

Cordially,

Daniel