REGRESSION on drm-tip

["Borah, Chaitanya Kumar" <chaitanya.kumar.borah@intel.com>]

Hello Christian,

This is Chaitanya (again!).

This mail is regarding another regression we are seeing in our CI 
runs[1] on drm-tip (with both xe and i915).

`````````````````````````````````````````````````````````````````````````````````
<4> [157.687644] ------------[ cut here ]------------
<4> [157.687768] WARNING: CPU: 5 PID: 2277 at kernel/freezer.c:139 
__set_task_frozen+0x7f/0xb0
...
<4> [157.687923] PKRU: 55555554
<4> [157.687924] Call Trace:
<4> [157.687925]  <TASK>
<4> [157.687926]  ? __pfx___set_task_frozen+0x10/0x10
<4> [157.687929]  task_call_func+0x6d/0x120
<4> [157.687932]  ? cgroup_freezing+0x89/0x200
<4> [157.687937]  freeze_task+0x98/0x100
<4> [157.687940]  try_to_freeze_tasks+0xd2/0x440
<4> [157.687946]  freeze_processes+0x56/0xd0
<4> [157.687948]  hibernate+0x129/0x4a0
<4> [157.687951]  state_store+0xd3/0xe0
<4> [157.687954]  kobj_attr_store+0x12/0x40
<4> [157.687959]  sysfs_kf_write+0x4d/0x80
<4> [157.687963]  kernfs_fop_write_iter+0x188/0x240
<4> [157.687967]  vfs_write+0x283/0x540
<4> [157.687969]  ? free_to_partial_list+0x46d/0x640
<4> [157.687976]  ksys_write+0x6f/0xf0
<4> [157.687980]  __x64_sys_write+0x19/0x30
<4> [157.687982]  x64_sys_call+0x79/0x26a0
<4> [157.687984]  do_syscall_64+0x93/0xd60
<4> [157.687987]  ? putname+0x65/0x90
<4> [157.687990]  ? kmem_cache_free+0x553/0x680
<4> [157.687995]  ? putname+0x65/0x90
<4> [157.687997]  ? putname+0x65/0x90
<4> [157.687999]  ? do_sys_openat2+0x8b/0xd0
<4> [157.688003]  ? __x64_sys_openat+0x54/0xa0
<4> [157.688007]  ? do_syscall_64+0x1b7/0xd60
<4> [157.688009]  ? __fput+0x1bf/0x2f0
<4> [157.688012]  ? fput_close_sync+0x3d/0xa0
<4> [157.688015]  ? __x64_sys_close+0x3e/0x90
<4> [157.688017]  ? do_syscall_64+0x1b7/0xd60
<4> [157.688019]  ? putname+0x65/0x90
<4> [157.688021]  ? putname+0x65/0x90
<4> [157.688023]  ? do_sys_openat2+0x8b/0xd0
<4> [157.688024]  ? __fput+0x1bf/0x2f0
<4> [157.688028]  ? __x64_sys_openat+0x54/0xa0
<4> [157.688032]  ? do_syscall_64+0x1b7/0xd60
<4> [157.688034]  ? do_syscall_64+0x1b7/0xd60
<4> [157.688036]  ? irqentry_exit+0x77/0xb0
<4> [157.688038]  ? exc_page_fault+0xbd/0x2c0
<4> [157.688042]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
<4> [157.688044] RIP: 0033:0x72523c91c574
`````````````````````````````````````````````````````````````````````````````````
Details log can be found in [2].

After bisecting the tree, the following patch [3] seems to be the first 
"bad" commit

`````````````````````````````````````````````````````````````````````````````````````````````````````````
commit a3f8f8662771285511ae26c4c8d3ba1cd22159b9
Author: Christian Brauner <brauner@kernel.org>
Date:   Wed Nov 5 14:39:45 2025 +0100

     power: always freeze efivarfs
`````````````````````````````````````````````````````````````````````````````````````````````````````````

We also verified that if we revert the patch the issue is not seen.

Could you please check why the patch causes this regression and provide 
a fix if necessary?

Thank you.

Regards

Chaitanya

[1]
https://intel-gfx-ci.01.org/tree/drm-tip/index.html?testfilter=suspend
[2]
https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_17595/shard-mtlp-6/igt@gem_exec_suspend@basic-s4-devices.html
[3] 
https://gitlab.com/freedesktop-mirror/drm-tip/-/commit/a3f8f8662771285511ae26c4c8d3ba1cd22159b9