[U-Boot] [PATCH v2] Correct corrupted NAND Flash access on KARO TX25 modules

[stefano babic <sbabic@denx.de>]

Am 02/04/2012 23:08, schrieb Marek Vasut:
> Dear Gachet Daniel,
> 
>> This patch v2 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).
>>
>> To solve the problem in a generic way, the proposition is to define a
>> specific value for that bit, CONFIG_NAND_MXC_NFC_ONE_CYCLE. This value
>> could be defined in the specific board configuration file
>> (./include/configs/...). Short description:
>>
>> CONFIG_NAND_MXC_NFC_ONE_CYCLE enables to specify how to access NAND flash
>> on the i.MX25 CPU. If CONFIG_NAND_MXC_NFC_ONE_CYCLE is defined, a
>> one-clock cycle will be used to access the NAND flash (symmetric mode);
>> otherwise a two-clock cycle will be used (asymmetric mode).
>>
>> Signed-off-by: Daniel Gachet <daniel.gachet@hefr.ch>
>> Cc: stefano babic <sbabic@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	2012-04-02 22:30:13.000000000 +0200
>> @@ -1290,7 +1290,9 @@ static void mxc_setup_config1(void)
>>  	uint16_t tmp;
>>
>>  	tmp = readw(&host->regs->nfc_config1);
>> +#ifdef CONFIG_NAND_MXC_NFC_ONE_CYCLE
>>  	tmp |= NFC_ONE_CYCLE;
>> +#endif
>>  	tmp |= NFC_4_8N_ECC;
>>  	writew(tmp, &host->regs->nfc_config1);
>>  	if (host->pagesize_2k)
>>
> 
> Won't this break other MX25 boards? Stefano?

Yes - please check my answer to your patch.

Best regards,
Stefano Babic

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