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

[Marek Vasut]

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.

-- 
Best regards,
Marek Vasut