New u-boot-aspeed-sdk runs slow and cause wdt2 timeout on ast2500

[Lei Yu]

> > > > Could you share us the boot log with timestamps?
> > > > It would be nice to know the time elapsed at each stage.
> > >
> > > Pasted to https://pastebin.com/emseqW6c
> > > It contains two logs, the first one is good, and the second has the issue.
>
> Working:
> [2022-02-23 02:47:03] U-Boot 2019.04 (Jan 24 2022 - 10:18:18 +0000)
> [2022-02-23 02:47:06] ## Loading kernel from FIT Image at 20100000 ...
> [2022-02-23 02:47:12] Starting kernel ...
>
> 3 + 6 seconds.
>
> broken:
> [2022-02-23 02:58:07] U-Boot 2019.04 (Feb 15 2022 - 07:22:14 +0000)
> [2022-02-23 02:58:12] ## Loading kernel from FIT Image at 20100000 ...
> [2022-02-23 02:58:22] Starting kernel ...
>
> 5 + 10 seconds.
>
> Interesting that the pre-hashing part is also slower.
>
> The old branch was based on v00.04.03. The new branch is based on v00.04.09.
>
> I wonder if this is the cause:
>
> $ git diff  v00.04.03..v00.04.09 -- configs/evb-ast2500_defconfig
> diff --git a/configs/evb-ast2500_defconfig b/configs/evb-ast2500_defconfig
> index 9fcf55b05ebb..000ed3f90bdd 100644
> --- a/configs/evb-ast2500_defconfig
> +++ b/configs/evb-ast2500_defconfig
> @@ -1,4 +1,5 @@
>  CONFIG_ARM=y
> +CONFIG_SYS_DCACHE_OFF=y
>  CONFIG_ARCH_ASPEED=y
>  CONFIG_SYS_TEXT_BASE=0x0
>  CONFIG_SYS_MALLOC_F_LEN=0x2000
>
> Lei, can you re-test with CONFIG_SYS_DCACHE_OFF=n ?
>

Yiwei helped to test with CONFIG_SYS_DCACHE_OFF=n, and it works fine now.
So it seems we get the root cause!