From mboxrd@z Thu Jan  1 00:00:00 1970
From: Bin Meng <bmeng.cn@gmail.com>
Date: Fri, 4 Sep 2020 09:48:58 +0800
Subject: RPi4 U-Boot freeze
In-Reply-To: <5ccb22ec4dd32d9ce283b14894ea39a6@agner.ch>
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 <5ccb22ec4dd32d9ce283b14894ea39a6@agner.ch>
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On Thu, Sep 3, 2020 at 7:23 PM Stefan Agner <stefan@agner.ch> wrote:
>
> Any thoughts on this issue?
>
> Just to be sure, I did some memory testing on the 2GB module, but no
> issues found.
>
> I still somehow suspected that something else might be wrong with my
> hardware, so I bought a new RPi4 (this time with 4GB of RAM) but the
> very same with that:
>
> U-Boot 2020.01 (Aug 23 2020 - 22:02:31 +0000)
>
> DRAM:  3.9 GiB
> <freeze>
>
> I still think there is something wrong with caching. From what I
> understand caches are enabled by the RPi (4) firmware. Is it safe to run
> 32-bit ARM U-Boot with enabled caches?
>
> --
> Stefan
>
> On 2020-08-23 19:06, Stefan Agner wrote:
> > Hi,
> >
> > I noticed a quite common freeze when running 32-bit U-Boot 2020.01
> > (rpi_4_32b_defconfig) on a 2GB RPi4 model:
> >
> > U-Boot 2020.01 (Aug 07 2020 - 13:00:23 +0000)
> >
> > DRAM:  1.9 GiB
> > <freeze, no more output>
> >
> > This happens fairly often, I would say 4 out of 5 boot tries. However,
> > if it boots, everything seems to run fine.
> >
> > The issue seems to go away when using 2020.04 or any newer release,
> > however, when trying to find the actual patch fixing the issue using git
> > bisect I ended up with a MMC merge request which really seems unrelated
> > (36bdcf7f3b). It seems that the problem is quite evasive and disappears
> > if certain structure are aligned differently etc.
> >
> > Enabling initcall debugging showed that U-Boot crashes right after
> > relocation:

I suspect there are some timing issues in the DDR training codes.

Regards,
Bin