PROBLEM: boot hang on ASUS P2B-F (regression)

[Nick Bowler]

Hi,

After updating my PC (ASUS P2B-F w/ Pentium 2 CPU) to the latest versions,
Linux now just hangs early on boot.  The last messages printed are:

  clocksource: tsc-early: mask: 0xffffffffffffffff max_cycles: 0x5c77f5216e, max_idle_ns: 440795213641 ns
  Calibrating delay loop (skipped), value calculated using timer frequency.. 801.87 BogoMIPS (lpj=4009380)

after which there is no further output or any indication of anything
happening at all.  (Complete log is attached, gzipped).

This is a regression from 6.17, which boots successfully.  Bisection
implicates the following:

  7eee1e92684507f64ec6a75fecbd27e37174b888 is the first bad commit
  commit 7eee1e92684507f64ec6a75fecbd27e37174b888 (HEAD)
  Author: Yazen Ghannam <yazen.ghannam@xxxxxxx>
  Date:   Mon Sep 8 15:40:34 2025 +0000
  
      x86/mce: Separate global and per-CPU quirks

This does not revert cleanly on top of 7.0-rc4.  However, the only
conflicts are in arch/x86/kernel/cpu/mce/amd.c, so I tried reverting
just the changes to core.c and intel.c, and this results in a kernel
that boots without any obvious problems.

Let me know if you need any more info!

Thanks,
  Nick

Attachment: p2dmesg.gz
Description: application/gzip