[U-Boot] SoCFPGA PL330 DMA driver and ECC scrubbing

[Marek Vasut <marex@denx.de>]

On 06/29/2018 04:44 PM, Jason Rush wrote:
> On 6/29/2018 9:34 AM, Marek Vasut wrote:
>> On 06/29/2018 04:31 PM, Jason Rush wrote:
>>> Dinh,
>> Hi,
>>
>>> A while ago, you posted the following patchset for SoCFPGA to add the PL330
>>> DMA driver, and updated the SoCFPGA SDRAM init to write zeros to SDRAM to
>>> initialize the ECC bits if ECC was enabled:
>>>
>>> https://lists.denx.de/pipermail/u-boot/2016-October/269643.html
>>>
>>> I know it's been a long time, so I'll summarize some of the conversation...
>>>
>>> At the time, you had a problem with the patchset causing the SPL to fail to
>>> find the MMC.  You had tracked it down to an issue with the following commit
>>> "a78cd8613204 ARM: Rework and correct barrier definitions".  You and Marek
>>> discussed it a bit, but I don't think there was a real conclusion.  You
>>> submitted a second version of the patchset asking for advice on debugging
>>> the issue:
>>>
>>> https://lists.denx.de/pipermail/u-boot/2016-December/275822.html
>>>
>>> No real conversation came from the second patchset, and that was the end of
>>> the patch.
>>>
>>> I was hoping we could revisit adding your patchset again. I am working on a
>>> custom SoCFPGA board with a Cyclone V and ECC SDRAM. I rebased your patchset
>>> against v2018.05 and it is working on my custom board (although I don't have
>>> an MMC). I also tested it on a SoCKit booting from an MMC (I forced it to
>>> scrub the SDRAM on the SoCKit, because it doesn't have ECC RAM), and the
>>> SoCKit finds the MMC and boots.
>>>
>>> I don't have any suggestions on why it is working now on my board and not
>>> back when you first submitted the patchset.  Maybe something else was fixed
>>> in the MMC? I was hoping you and Marek could test this patch again on some
>>> different SoCFPGA boards to see if you get the same results.
>> Look at this patch
>> http://git.denx.de/?p=u-boot/u-boot-socfpga.git;a=commit;h=9bb8a249b292d26f152c20e3641600b3d7b3924b
>>
>> You likely want similar approach, it's faster then the DMA and much simpler.
>>
> Thanks Marek.  I'll give it a try.  Would you be interested in a similar patch for the Gen 5?

I don't have any Gen5 board which uses ECC, do you ?
If so, yes, prepare a patch, it should be very similar.

Make sure to measure how long it takes to scrub the memory and how much
memory you have, I'd be interested in the numbers.

-- 
Best regards,
Marek Vasut