PROBLEM: boot hang on Indy R4400SC (regression)

[Nick Bowler]

Hi,

After a recent 6.1.y stable kernel update, my Indy (mips64 R4400SC) now
just stops booting early, just before when I would normally see the
kernel messages about mounting the root filesystem.

There are no further messages of any kind, and the boot process does not
appear to ever complete.  However, the kernel is not fully crashed, as
it does respond to sysrq commands from the keyboard (and I do get output
on the console from these).

I bisected to the following:
  
    794b679a28bb59a4533ae39a7cf945b9d5bbe336 is the first bad commit
    commit 794b679a28bb59a4533ae39a7cf945b9d5bbe336
    Author: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
    Date:   Sat Jun 7 13:43:56 2025 +0100
    
        MIPS: mm: tlb-r4k: Uniquify TLB entries on init
    
        commit 35ad7e181541aa5757f9f316768d3e64403ec843 upstream.

This reverts cleanly on top of 6.1.158 and the resulting kernel boots
normally.  I then reproduced this failure on 6.18-rc4.  Reverting
35ad7e181541 on top of 6.18-rc4 also results in a normal boot.

Let me know if you need any more info!

Thanks,
  Nick