[PATCH] omap3_beagle: Change NAND ECC scheme back to OMAP_ECC_HAM1_CODE_HW

[Patrik Dahlstrom]

On 12/22/19 4:24 AM, Derald D. Woods wrote:
> On Sat, Dec 21, 2019 at 05:18:22PM +0100, Patrik Dahlström wrote:
>> The omap3_beagle NAND ECC scheme was changed in 4b37928d357 for unknown
>> reasons, leading to uncorrectible ecc errors. This commit changes it
>> back to what it was before.
>>
> 
> Hello Patrick,
> 
> Is there a setup/test that you are using for OMAP_ECC_HAM1_CODE_HW? I
> just want to give it a try. I have three OMAP3 boards, with NAND, that
> I would like to test.

I'm using a BeagleBoard rev. C4 (yes, the one that came out in 2009)
for testing.

> 
> I also see that the SYS_NAND_ECC_BYTES should have been changed to '14'
> per the 'doc/README.nand' for OMAP_ECC_BCH8_CODE_HW_DETECTION_SW. This
> may be the issue with this particular ECC scheme.
> 
I based my changes on reverting 4b37928d357, which did this:

<snip>
 +#define CONFIG_NAND_OMAP_ECCSCHEME      OMAP_ECC_BCH8_CODE_HW_DETECTION_SW
<snip>
 -#define CONFIG_NAND_OMAP_ECCSCHEME     OMAP_ECC_HAM1_CODE_HW
<snip>

Based on your comment, I tested this configuration:

 #define CONFIG_SYS_NAND_ECCBYTES        14
 #define CONFIG_NAND_OMAP_ECCSCHEME      OMAP_ECC_BCH8_CODE_HW_DETECTION_SW

It worked to boot from SD card (only had to do saveenv), but only
partly from NAND:

 U-Boot SPL 2020.01-rc5-00006-gda26dd89c8-dirty (Dec 22 2019 - 09:26:14 +0100)
 Trying to boot from NAND

Then it just hangs. Here's how I flashed SPL and U-Boot:

 mmc rescan
 fatload mmc 0 80000000 MLO
 nand erase 0 80000
 nandecc hw
 cp.b 80000000 80020000 20000
 cp.b 80000000 80040000 20000
 cp.b 80000000 80060000 20000
 nand write 80000000 0 80000
 fatload mmc 0 80000000 u-boot.img
 nand erase 80000 160000
 nand write 80000000 80000 160000

I then tried adjusting the "nandecc hw" line, but here's how that went:

 BeagleBoard # nandecc hw bch8
 nand: error: CONFIG_NAND_OMAP_ELM required for ECC

Unfortunately CONFIG_NAND_OMAP_ELM is not available for OMAP34XX.

> Derald
> 
> 
>> Signed-off-by: Patrik Dahlström <risca at dalakolonin.se>
>> ---
>>  include/configs/omap3_beagle.h | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/include/configs/omap3_beagle.h b/include/configs/omap3_beagle.h
>> index 4157d7614f..bc8aa7adf5 100644
>> --- a/include/configs/omap3_beagle.h
>> +++ b/include/configs/omap3_beagle.h
>> @@ -37,7 +37,7 @@
>>                                           10, 11, 12, 13}
>>  #define CONFIG_SYS_NAND_ECCSIZE         512
>>  #define CONFIG_SYS_NAND_ECCBYTES        3
>> -#define CONFIG_NAND_OMAP_ECCSCHEME      OMAP_ECC_BCH8_CODE_HW_DETECTION_SW
>> +#define CONFIG_NAND_OMAP_ECCSCHEME      OMAP_ECC_HAM1_CODE_HW
>>  #define CONFIG_SYS_NAND_U_BOOT_OFFS     0x80000
>>  #define CONFIG_SYS_ENV_SECT_SIZE        SZ_128K
>>  #define CONFIG_ENV_OVERWRITE
>> -- 
>> 2.17.1
>>