[U-Boot] [PATCH] arm: socfpga: dm: Fix DM initialization failure after warm reset

[Simon Glass]

Hi,

On 3 September 2015 at 05:14, Marek Vasut <marex at denx.de> wrote:
> On Thursday, September 03, 2015 at 01:12:03 PM, Jian Luo wrote:
>> On 03.09.2015 12:46, Marek Vasut wrote:
>>  > On Thursday, September 03, 2015 at 12:17:13 PM, Jian Luo wrote:
>>  >
>>  > Hi!
>>  >
>>  > [...]
>>  >
>>  >>  >> Yes, I can. But U-Boot can still have problem with other Image
>>  >>  >> which disables ECC.
>>  >>  >> I found another post related to this problem
>>  >>  >> https://lkml.org/lkml/2015/2/6/685 .
>>  >>  >>
>>  >>  >>      Quote: To initialize ECC, the OCRAM needs to enable ECC
>>
>> then clear
>>
>>  >>  >> the entire
>>  >>  >>
>>  >>  >>      memory to zero before using it.
>>  >>
>>  >> Hi!
>>  >>
>>  >>  > Oh, but that is a problem, since we're running from the OCRAM
>>
>> ourselves,
>>
>>  >>  > thus we cannot clear the OCRAM. Maybe we should force-disable the
>>  >>  > ECC instead? But can we be sure that the corruption does not happen
>>  >>  > when you disable ECC ?
>>  >>
>>  >> Yes, that will be a problem. It's also why I let the
>>  >> SYSMGR_ECC_OCRAM_EN bit intact in the patch.
>>  >
>>  > OK, but what about turning the ECC off in the SPL, will that also
>>
>> introduce
>>
>>  > corruption or not ? That might be the right fix, no ?
>>
>> Hi Marek,
>>
>> Sorry, I don't know the detail of ECC implementation in socfpga.
>> Dinh might have the answer to that.
>>
>> Anyhow I still think let the setting untouched is the safest fix.
>> SPL should use the same ECC setting which BROM loads SPL with.
>
> That's right, but I'd also like to have this bit in some defined
> state from the boot instead of having this in some random setting.
> Dinh, can you comment on this corruption please ?

Also I'm still a bit confused.

The code in crt0.S zeroes global_data so how can it be non-zero a
little later in board_init_f()?

Regards,
Simon