RE: Pressing the power button causes the device to freeze completely

["Sagatov, Evgeniy" <esagatov@amt.ru>]

Hello Thorsten,

Thanks for the detailed manual!

I determined that the problem started between versions 6.7.12 and 6.8-rc1. Then I ran a 'git bisect' according to the manual.

Result:
b0d326da462e20285236e11e4cbc32085de9f363 is the first bad commit
commit b0d326da462e20285236e11e4cbc32085de9f363
Merge: 8c94ccc7cd69 e37617c8e53a
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Thu Jan 18 11:57:33 2024 -0800

    Merge tag 'sched-urgent-2024-01-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

    Pull scheduler fix from Ingo Molnar:
     "Fix a cpufreq related performance regression on certain systems, where
      the CPU would remain at the lowest frequency, degrading performance
      substantially"

    * tag 'sched-urgent-2024-01-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
      sched/fair: Fix frequency selection for non-invariant case

 kernel/sched/cpufreq_schedutil.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

----
Sincerely, Evgeny Sagatov

 ----------------
16.04.2026, 20:35, Thorsten Leemhuis (mailto:regressions@leemhuis.info):
To: Evgeny Sagatov (mailto:sagatov@ya.ru), Rafael J. Wysocki (mailto:rafael.j.wysocki@intel.com);
Copy: mailto:regressions@lists.linux.dev, LKML (mailto:linux-kernel@vger.kernel.org), Michal Wilczynski (mailto:michal.wilczynski@intel.com);
Topic: Pressing the power button causes the device to freeze completely;
 
On 4/16/26 19:22, Evgeny Sagatov wrote:
 Could you please try 7.0 as well?
 I compiled 7.0.0 kernel from sources.
 Unfortunately, this kernel also freezes when the power button is pressed.

Thx for testing.
  
 How did you find that this causes the problem? Did you do a proper
 bisection and thus checked if the parent of that commit really works?
  
 I don't think I did it correctly.
 Because the previous commits didn't shut down the PC or cause it to
 freeze. I think they just weren't working.
  
 I also tried a very simple module tity-power-button. Pressing the power
 button when using this module also causes a full freeze.
 I think the problem lies with the ACPI functionality, but none of kernel
 options helped fix it.
  
 I'm confused.

Then you likely want to properly bisect the bug. Might be best to do
that on a Debian 12 install (where everything used to be working) by
following this guide:

https://docs.kernel.org/admin-guide/verify-bugs-and-bisect-regressions.html

But be warned: the regression is old. Even if the culprit is identified
the usual rules wrt to "no regression" might not apply, as fixing the
regression could cause regressions for other users.

Ciao, Thorsten
 
 ----------------
 To: Evgeny Sagatov (mailto:sagatov@ya.ru), Rafael J. Wysocki
 (mailto:rafael.j.wysocki@intel.com);
 Copy: mailto:regressions@lists.linux.dev, LKML (mailto:linux-kernel@vger.kernel.org),
 Michal Wilczynski (mailto:michal.wilczynski@intel.com);
 Topic: Pressing the power button causes the device to freeze completely;
 16.04.2026, 11:23, "Thorsten Leemhuis" <mailto:regressions@leemhuis.info>:
 
     [removing the stable list, this is not something for them]
 
     On 4/13/26 18:46, Evgeny Sagatov wrote:
 
          I have a PC with a motherboard GA-EP45T-UD3LR (Rev. 1.0) <https://
          https://www.gigabyte.com/Motherboard/GA-EP45T-UD3LR-rev-10 <https://
         https://www.gigabyte.com/Motherboard/GA-EP45T-UD3LR-rev-10>> and
         processor Intel
          Core 2 Quad Q9550.
          Previously, I had Debian 12 with kernel 6.1 installed, and
         pressing the
          power button would shut down the PC as usual.
          I updated to Debian 13 with kernel 6.12.74, and now pressing
         the power
          button causes the PC to freeze completely.
           
          I see that systemd doesn't even begin to shut down. It freezes
          immediately after pressing the button. There's no error message in
          console. There's no error message in the logs either.
         Netconsole doesn't
          report any errors, and the kernel doesn't panic. It just
         freezes completely.
           
          I checked that Live CD with Debian 12 continue to shut down
         normally,
          but Live CD with Debian 13 freeze.
          I tried updating and resetting the BIOS. I tried various kernel
          parameters related to ACPI settings. I also tried kernels 6.18
         and 6.19.
          Nothing fixed the problem.
 
 
     Could you please try 7.0 as well? It contains a fix for the commit you
     mentioned below.
      
 
           
          If I unload the "button" module, the system doesn't freeze, but
         it also
          doesn't shut down.
          I built "button" module by rolling back its version to commit
         1a20d40
          <https://github.com/torvalds/linux/ <https://github.com/
         torvalds/linux/>
          commit/1a20d409c874255086e2f42a729826d490294c91>, which
         corresponds to
          kernel version 6.1. This module does not freeze, but does not
         turn off
          the PC either.
           
          I've found that the freezes have been occurring since commit
         0d51157
          <https://github.com/torvalds/linux/ <https://github.com/
         torvalds/linux/>
          commit/0d51157dfaac05ea66616d8a250dce04bef49a4f>.
 
 
     That is 0d51157dfaac05 ("ACPI: button: Eliminate the driver notify
     callback") [v6.5-rc1] from Rafael. But that is a very old commit; and
     you seem to be switching distro versions and kernel at the same time,
     which could interfere.
 
     How did you find that this causes the problem? Did you do a proper
     bisection and thus checked if the parent of that commit really works?
      
 
          Unfortunately, my skills are not enough to understand the
         reason for the
          freeze.
           
          I'm attaching dmesg and lspci logs.
 
     Ciao, Thorsten