Re: [PATCH] MIPS: ralink: mt7621: do memory detection on KSEG1

From: Rui Salvaterra
Date: Fri Feb 11 2022 - 03:46:25 EST


Hi, Guo,

On Fri, 11 Feb 2022 at 00:14, Chuanhong Guo <gch981213@xxxxxxxxx> wrote:
>
> It's reported that current memory detection code occasionally detects
> larger memory under some bootloaders.
> Current memory detection code tests whether address space wraps around
> on KSEG0, which is unreliable because it's cached.
>
> Rewrite memory size detection to perform the same test on KSEG1 instead.
> While at it, this patch also does the following two things:
> 1. use a fixed pattern instead of a random function pointer as the magic
> value.
> 2. add an additional memory write and a second comparison as part of the
> test to prevent possible smaller memory detection result due to
> leftover values in memory.

[patch snipped]

No issues here, and it does seem to have fixed the RAM size detection
on my Redmi AC2100. It's always been a very sporadic failure here, so
I'll be keeping an eye on it to see if there are any further
misdetections. :)
In any case, feel free to add my

Tested-by: Rui Salvaterra <rsalvaterra@xxxxxxxxx>

Thanks,
Rui