Hi Stefano and Marek,
-----Original Message-----
From: stefano babic [mailto:sba...@denx.de]
Sent: dimanche 1 avril 2012 12:33
To: Gachet Daniel
Cc: u-boot@lists.denx.de
Subject: Re: [U-Boot] [PATCH] Correct corrupted NAND Flash access on KARO TX25
modules
>Am 31/03/2012 09:31, schrieb 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.gac...@hefr.ch>
>> Cc: Wolfgang Denk <w...@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
>> @@ -1290,7 +1290,9 @@ static void mxc_setup_config1(void)
>> uint16_t tmp;
>>
>> tmp = readw(&host->regs->nfc_config1);
>> +#ifndef MACH_TYPE_TX25
>> tmp |= NFC_ONE_CYCLE;
>> +#endif
>
>NAK. We cleaned up all u-boot occurrencies of machine id, except the machid
>passed to the kernel. And when the
>device tree will be effective, also the machid will be obsolete.
>
>This change seems not strictly related to the Karo's SOM, but it it a
>configuration of the mxc_nand driver, such as
>CONFIG_NAND_MXC_V1_1. You can add a CONFIG_NAND_MXC_* value (please add
>documentation, too) and use it in the driver code.
>
>Can I also ask you if the same setup is used in the Linux driver (this SOM is
>not mainlined, I suppose you have a porting from the
>manufacturer) ? As far as I can see, this setup is not used for the
>Freescale's mx25pdk (the only MX25 board in mainline kernel).
>
>Best regards,
>Stefano Babic
>
>--
>=====================================================================
>DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
>HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
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>=====================================================================
I found the proposition of Stefano very interesting. My proposition will be to
define a specific value for that bit, for instance
CONFIG_NAND_MXC_V1_1_NFC_ONE_CYCLE. If this value is defined, the NFC_ONE_CYCLE
bit will be set, otherwise not.
This value could be defined in the specific board configuration file
(./include/configs/...).
The patch will be the following:
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 2012-04-01 21:07:13.000000000 +0200
@@ -1290,7 +1290,9 @@ static void mxc_setup_config1(void)
uint16_t tmp;
tmp = readw(&host->regs->nfc_config1);
+#ifdef CONFIG_NAND_MXC_V1_1_NFC_ONE_CYCLE
tmp |= NFC_ONE_CYCLE;
+#endif
tmp |= NFC_4_8N_ECC;
writew(tmp, &host->regs->nfc_config1);
if (host->pagesize_2k)
Is that a valuable solution for you?
Cordially,
Daniel
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