Bug 489169

Summary:	Powerdevil crashes a lot in ddc_close_display() after update to Plasma 6.1.0
Product:	[Unmaintained] Powerdevil	Reporter:	Pavel Urusov <pavel.urusov>
Component:	general	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	RESOLVED FIXED
Severity:	crash	CC:	auxsvr, ben.schroeder, eugene.savitsky, jai.mu, jpetso, kde.h2vne, madLyfe, me, me, natalie_clarius, nate, sam, smowtenshi
Priority:	HI	Keywords:	regression
Version First Reported In:	6.1.0
Target Milestone:	---
Platform:	openSUSE
OS:	Linux
Latest Commit:	https://invent.kde.org/plasma/powerdevil/-/commit/209782d50796d8aa2bfe36753c69ed6c77ec5c99	Version Fixed/Implemented In:	6.1.2
Sentry Crash Report:

Description Pavel Urusov 2024-06-25 11:04:39 UTC

SUMMARY
Power management is completely broken after update to Plasma 6.1.0:

1) The screen brightness control does not work (I can adjust the slider, but the monitor brightness stays the same)
2) The power profile selector does not work, the PC is stuck in the Performance mode
3) In addition to that, the powerdevil service crashes every time I try to adjust any power-related settings (e.g. change the screen brightness or switch power profiles)

STEPS TO REPRODUCE
1. Update Plasma to 6.1.0
2. Try to use any power-related adjustment 

OBSERVED RESULT
It is impossible to adjust the screen brightness or switch power profiles, and the powerdevil service crashes every time the user tries to use any power-related settings.

EXPECTED RESULT
It is possible to adjust the screen brightness or switch power profiles, and the powerdevil service does not crash.

SOFTWARE/OS VERSIONS
Operating System: openSUSE Tumbleweed 20240622
KDE Plasma Version: 6.1.0
KDE Frameworks Version: 6.3.0
Qt Version: 6.7.1
Kernel Version: 6.9.5-1-default (64-bit)
Graphics Platform: Wayland
Processors: 20 × 12th Gen Intel® Core™ i7-12700
Memory: 31.1 GiB of RAM
Graphics Processor: AMD Radeon RX 560 Series

ADDITIONAL INFORMATION
           PID: 2292 (org_kde_powerde)
           UID: 1000 (pavel)
           GID: 1000 (pavel)
        Signal: 6 (ABRT)
     Timestamp: Tue 2024-06-25 10:48:03 IST (58min ago)
  Command Line: /usr/libexec/org_kde_powerdevil
    Executable: /usr/libexec/org_kde_powerdevil
 Control Group: /user.slice/user-1000.slice/user@1000.service/background.slice/plasma-powerdevil.service
          Unit: user@1000.service
     User Unit: plasma-powerdevil.service
         Slice: user-1000.slice
     Owner UID: 1000 (pavel)
       Boot ID: 6a221f40037b493682be53d27392b38f
    Machine ID: d73c056243bd4d7cacef2905f9de4ea0
      Hostname: pyrus
       Storage: /var/lib/systemd/coredump/core.org_kde_powerde.1000.6a221f40037b493682be53d27392b38f.2292.1719308883000000.zst (present)
  Size on Disk: 2.4M
       Message: Process 2292 (org_kde_powerde) of user 1000 dumped core.
                
                Stack trace of thread 2544:
                #0  0x00007f75fd2949dc __pthread_kill_implementation (libc.so.6 + 0x949dc)
                #1  0x00007f75fd241176 raise (libc.so.6 + 0x41176)
                #2  0x00007f75fee54c03 _ZN6KCrash19defaultCrashHandlerEi (libKF6Crash.so.6 + 0x6c03)
                #3  0x00007f75fd241240 __restore_rt (libc.so.6 + 0x41240)
                #4  0x00007f75fd2949dc __pthread_kill_implementation (libc.so.6 + 0x949dc)
                #5  0x00007f75fd241176 raise (libc.so.6 + 0x41176)
                #6  0x00007f75fd228917 abort (libc.so.6 + 0x28917)
                #7  0x00007f75fc0d8025 n/a (libglib-2.0.so.0 + 0x23025)
                #8  0x00007f75fc13f77a g_assertion_message_expr (libglib-2.0.so.0 + 0x8a77a)
                #9  0x00007f75fc0fecff n/a (libglib-2.0.so.0 + 0x49cff)
                #10 0x00007f75fc100a27 g_hash_table_remove (libglib-2.0.so.0 + 0x4ba27)
                #11 0x00007f75fd151702 n/a (libddcutil.so.5 + 0x34702)
                #12 0x00007f75fd192bcc ddca_close_display (libddcutil.so.5 + 0x75bcc)
                #13 0x00007f75fee161e6 n/a (libpowerdevilcore.so.2 + 0x571e6)
                #14 0x00007f75fdbd1fbb _ZN7QObject5eventEP6QEvent (libQt6Core.so.6 + 0x1d1fbb)
                #15 0x00007f75fdb8ee20 _ZN16QCoreApplication15notifyInternal2EP7QObjectP6QEvent (libQt6Core.so.6 + 0x18ee20)
                #16 0x00007f75fdb8f180 _ZN23QCoreApplicationPrivate16sendPostedEventsEP7QObjectiP11QThreadData (libQt6Core.so.6 + 0x18f180)
                #17 0x00007f75fddc2973 n/a (libQt6Core.so.6 + 0x3c2973)
                #18 0x00007f75fc112740 n/a (libglib-2.0.so.0 + 0x5d740)
                #19 0x00007f75fc114388 n/a (libglib-2.0.so.0 + 0x5f388)
                #20 0x00007f75fc114a3c g_main_context_iteration (libglib-2.0.so.0 + 0x5fa3c)
                #21 0x00007f75fddc147c _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt6Core.so.6 + 0x3c147c)
                #22 0x00007f75fdb9959b _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt6Core.so.6 + 0x19959b)
                #23 0x00007f75fdc74ad4 _ZN7QThread4execEv (libQt6Core.so.6 + 0x274ad4)
                #24 0x00007f75fdced139 n/a (libQt6Core.so.6 + 0x2ed139)
                #25 0x00007f75fd292ba2 start_thread (libc.so.6 + 0x92ba2)
                #26 0x00007f75fd31400c __clone3 (libc.so.6 + 0x11400c)
                
                Stack trace of thread 2344:
                #0  0x00007f75fd28efee __futex_abstimed_wait_common (libc.so.6 + 0x8efee)
                #1  0x00007f75fd291d30 pthread_cond_wait@@GLIBC_2.3.2 (libc.so.6 + 0x91d30)
                #2  0x00007f75edd1c639 n/a (radeonsi_dri.so + 0x11c639)
                #3  0x00007f75edcfc7db n/a (radeonsi_dri.so + 0xfc7db)
                #4  0x00007f75edd1c577 n/a (radeonsi_dri.so + 0x11c577)
                #5  0x00007f75fd292ba2 start_thread (libc.so.6 + 0x92ba2)
                #6  0x00007f75fd31400c __clone3 (libc.so.6 + 0x11400c)
                
                Stack trace of thread 2338:
                #0  0x00007f75fd28efee __futex_abstimed_wait_common (libc.so.6 + 0x8efee)
                #1  0x00007f75fd291d30 pthread_cond_wait@@GLIBC_2.3.2 (libc.so.6 + 0x91d30)
                #2  0x00007f75edd1c639 n/a (radeonsi_dri.so + 0x11c639)
                #3  0x00007f75edcfc7db n/a (radeonsi_dri.so + 0xfc7db)
                #4  0x00007f75edd1c577 n/a (radeonsi_dri.so + 0x11c577)
                #5  0x00007f75fd292ba2 start_thread (libc.so.6 + 0x92ba2)
                #6  0x00007f75fd31400c __clone3 (libc.so.6 + 0x11400c)
                
                Stack trace of thread 2346:
                #0  0x00007f75fd28efee __futex_abstimed_wait_common (libc.so.6 + 0x8efee)
                #1  0x00007f75fd291d30 pthread_cond_wait@@GLIBC_2.3.2 (libc.so.6 + 0x91d30)
                #2  0x00007f75edd1c639 n/a (radeonsi_dri.so + 0x11c639)
                #3  0x00007f75edcfc7db n/a (radeonsi_dri.so + 0xfc7db)
                #4  0x00007f75edd1c577 n/a (radeonsi_dri.so + 0x11c577)
                #5  0x00007f75fd292ba2 start_thread (libc.so.6 + 0x92ba2)
                #6  0x00007f75fd31400c __clone3 (libc.so.6 + 0x11400c)
                
                Stack trace of thread 2361:
                #0  0x00007f75fd30578f __poll (libc.so.6 + 0x10578f)
                #1  0x00007f75fc11432f n/a (libglib-2.0.so.0 + 0x5f32f)
                #2  0x00007f75fc114c5f g_main_loop_run (libglib-2.0.so.0 + 0x5fc5f)
                #3  0x00007f75f7fd1206 n/a (libgio-2.0.so.0 + 0x127206)
                #4  0x00007f75fc14130e n/a (libglib-2.0.so.0 + 0x8c30e)
                #5  0x00007f75fd292ba2 start_thread (libc.so.6 + 0x92ba2)
                #6  0x00007f75fd31400c __clone3 (libc.so.6 + 0x11400c)
                
                Stack trace of thread 2347:
                #0  0x00007f75fd28efee __futex_abstimed_wait_common (libc.so.6 + 0x8efee)
                #1  0x00007f75fd291d30 pthread_cond_wait@@GLIBC_2.3.2 (libc.so.6 + 0x91d30)
                #2  0x00007f75edd1c639 n/a (radeonsi_dri.so + 0x11c639)
                #3  0x00007f75edcfc7db n/a (radeonsi_dri.so + 0xfc7db)
                #4  0x00007f75edd1c577 n/a (radeonsi_dri.so + 0x11c577)
                #5  0x00007f75fd292ba2 start_thread (libc.so.6 + 0x92ba2)
                #6  0x00007f75fd31400c __clone3 (libc.so.6 + 0x11400c)
                
                Stack trace of thread 2320:
                #0  0x00007f75fd30578f __poll (libc.so.6 + 0x10578f)
                #1  0x00007f75fc11432f n/a (libglib-2.0.so.0 + 0x5f32f)
                #2  0x00007f75fc114a3c g_main_context_iteration (libglib-2.0.so.0 + 0x5fa3c)
                #3  0x00007f75fddc147c _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt6Core.so.6 + 0x3c147c)
                #4  0x00007f75fdb9959b _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt6Core.so.6 + 0x19959b)
                #5  0x00007f75fdc74ad4 _ZN7QThread4execEv (libQt6Core.so.6 + 0x274ad4)
                #6  0x00007f75fe17b70a n/a (libQt6DBus.so.6 + 0x3870a)
                #7  0x00007f75fdced139 n/a (libQt6Core.so.6 + 0x2ed139)
                #8  0x00007f75fd292ba2 start_thread (libc.so.6 + 0x92ba2)
                #9  0x00007f75fd31400c __clone3 (libc.so.6 + 0x11400c)
                
                Stack trace of thread 2322:
                #0  0x00007f75fd30578f __poll (libc.so.6 + 0x10578f)
                #1  0x00007f75fb376dd1 n/a (libQt6WaylandClient.so.6 + 0x7cdd1)
                #2  0x00007f75fdced139 n/a (libQt6Core.so.6 + 0x2ed139)
                #3  0x00007f75fd292ba2 start_thread (libc.so.6 + 0x92ba2)
                #4  0x00007f75fd31400c __clone3 (libc.so.6 + 0x11400c)
                
                Stack trace of thread 2292:
                #0  0x00007f75fd30578f __poll (libc.so.6 + 0x10578f)
                #1  0x00007f75fc11432f n/a (libglib-2.0.so.0 + 0x5f32f)
                #2  0x00007f75fc114a3c g_main_context_iteration (libglib-2.0.so.0 + 0x5fa3c)
                #3  0x00007f75fddc147c _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt6Core.so.6 + 0x3c147c)
                #4  0x00007f75fdb9959b _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt6Core.so.6 + 0x19959b)
                #5  0x00007f75fdb92da6 _ZN16QCoreApplication4execEv (libQt6Core.so.6 + 0x192da6)
                #6  0x000056027bff32af n/a (org_kde_powerdevil + 0xa2af)
                #7  0x00007f75fd22a1f0 __libc_start_call_main (libc.so.6 + 0x2a1f0)
                #8  0x00007f75fd22a2b9 __libc_start_main@@GLIBC_2.34 (libc.so.6 + 0x2a2b9)
                #9  0x000056027bff3525 n/a (org_kde_powerdevil + 0xa525)
                
                Stack trace of thread 2340:
                #0  0x00007f75fd28efee __futex_abstimed_wait_common (libc.so.6 + 0x8efee)
                #1  0x00007f75fd291d30 pthread_cond_wait@@GLIBC_2.3.2 (libc.so.6 + 0x91d30)
                #2  0x00007f75edd1c639 n/a (radeonsi_dri.so + 0x11c639)
                #3  0x00007f75edcfc7db n/a (radeonsi_dri.so + 0xfc7db)
                #4  0x00007f75edd1c577 n/a (radeonsi_dri.so + 0x11c577)
                #5  0x00007f75fd292ba2 start_thread (libc.so.6 + 0x92ba2)
                #6  0x00007f75fd31400c __clone3 (libc.so.6 + 0x11400c)
                
                Stack trace of thread 2546:
                #0  0x00007f75fd30578f __poll (libc.so.6 + 0x10578f)
                #1  0x00007f75fc11432f n/a (libglib-2.0.so.0 + 0x5f32f)
                #2  0x00007f75fc114a3c g_main_context_iteration (libglib-2.0.so.0 + 0x5fa3c)
                #3  0x00007f75fddc147c _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt6Core.so.6 + 0x3c147c)
                #4  0x00007f75fdb9959b _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt6Core.so.6 + 0x19959b)
                #5  0x00007f75fdc74ad4 _ZN7QThread4execEv (libQt6Core.so.6 + 0x274ad4)
                #6  0x00007f75fdced139 n/a (libQt6Core.so.6 + 0x2ed139)
                #7  0x00007f75fd292ba2 start_thread (libc.so.6 + 0x92ba2)
                #8  0x00007f75fd31400c __clone3 (libc.so.6 + 0x11400c)
                
                Stack trace of thread 2343:
                #0  0x00007f75fd28efee __futex_abstimed_wait_common (libc.so.6 + 0x8efee)
                #1  0x00007f75fd291d30 pthread_cond_wait@@GLIBC_2.3.2 (libc.so.6 + 0x91d30)
                #2  0x00007f75edd1c639 n/a (radeonsi_dri.so + 0x11c639)
                #3  0x00007f75edcfc7db n/a (radeonsi_dri.so + 0xfc7db)
                #4  0x00007f75edd1c577 n/a (radeonsi_dri.so + 0x11c577)
                #5  0x00007f75fd292ba2 start_thread (libc.so.6 + 0x92ba2)
                #6  0x00007f75fd31400c __clone3 (libc.so.6 + 0x11400c)
                
                Stack trace of thread 2359:
                #0  0x00007f75fd311bcd syscall (libc.so.6 + 0x111bcd)
                #1  0x00007f75fc16ed50 g_cond_wait (libglib-2.0.so.0 + 0xb9d50)
                #2  0x00007f75fc0dd0db n/a (libglib-2.0.so.0 + 0x280db)
                #3  0x00007f75fc141aa2 n/a (libglib-2.0.so.0 + 0x8caa2)
                #4  0x00007f75fc14130e n/a (libglib-2.0.so.0 + 0x8c30e)
                #5  0x00007f75fd292ba2 start_thread (libc.so.6 + 0x92ba2)
                #6  0x00007f75fd31400c __clone3 (libc.so.6 + 0x11400c)
                
                Stack trace of thread 2360:
                #0  0x00007f75fd30578f __poll (libc.so.6 + 0x10578f)
                #1  0x00007f75fc11432f n/a (libglib-2.0.so.0 + 0x5f32f)
                #2  0x00007f75fc114a3c g_main_context_iteration (libglib-2.0.so.0 + 0x5fa3c)
                #3  0x00007f75fc114a81 n/a (libglib-2.0.so.0 + 0x5fa81)
                #4  0x00007f75fc14130e n/a (libglib-2.0.so.0 + 0x8c30e)
                #5  0x00007f75fd292ba2 start_thread (libc.so.6 + 0x92ba2)
                #6  0x00007f75fd31400c __clone3 (libc.so.6 + 0x11400c)
                
                Stack trace of thread 2323:
                #0  0x00007f75fd30578f __poll (libc.so.6 + 0x10578f)
                #1  0x00007f75fb376dd1 n/a (libQt6WaylandClient.so.6 + 0x7cdd1)
                #2  0x00007f75fdced139 n/a (libQt6Core.so.6 + 0x2ed139)
                #3  0x00007f75fd292ba2 start_thread (libc.so.6 + 0x92ba2)
                #4  0x00007f75fd31400c __clone3 (libc.so.6 + 0x11400c)
                ELF object binary architecture: AMD x86-64

Comment 1 Nate Graham 2024-06-25 14:38:19 UTC

Let's take it one thing at a time. Powerdevil crashing is clearly not good, and may be the root cause of the other issues. Let's debug that. Can you get a backtrace with debug symbols of the crashing thread? The one you pasted is obfuscated, shows everything, and is missing debug symbols.

See https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports#Retrieving_a_backtrace_using_coredumpctl to learn how to do this.

Comment 2 Pavel Urusov 2024-06-25 15:43:01 UTC

[Thread debugging using libthread_db enabled]                                                                                                                                                                                                                                   
Using host libthread_db library "/lib64/libthread_db.so.1".
Core was generated by `/usr/libexec/org_kde_powerdevil'.
Program terminated with signal SIGABRT, Aborted.
#0  __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44
44            return INTERNAL_SYSCALL_ERROR_P (ret) ? INTERNAL_SYSCALL_ERRNO (ret) : 0;
[Current thread is 1 (Thread 0x7f75d56006c0 (LWP 2544))]
Missing separate debuginfos, use: zypper install libdrm_amdgpu1-debuginfo-2.4.121-1.1.x86_64 libpciaccess0-debuginfo-0.18.1-1.2.x86_64 libpolkit-gobject-1-0-debuginfo-123-2.3.x86_64 libsasl2-3-debuginfo-2.1.28-8.1.x86_64 libwayland-server0-debuginfo-1.23.0-1.1.x86_64 libxcb-dri2-0-debuginfo-1.17.0-1.1.x86_64 libxcb-dri3-0-debuginfo-1.17.0-1.1.x86_64 libxshmfence1-debuginfo-1.3.2-1.4.x86_64
(gdb) bt
#0  __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44
#1  0x00007f75fd294a63 in __pthread_kill_internal (signo=6, threadid=<optimized out>) at pthread_kill.c:78
#2  0x00007f75fd241176 in __GI_raise (sig=6) at ../sysdeps/posix/raise.c:26
#3  0x00007f75fee54c03 in KCrash::defaultCrashHandler (sig=6) at /usr/src/debug/kcrash-6.3.0/src/kcrash.cpp:597
#4  <signal handler called>
#5  __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44
#6  0x00007f75fd294a63 in __pthread_kill_internal (signo=6, threadid=<optimized out>) at pthread_kill.c:78
#7  0x00007f75fd241176 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26
#8  0x00007f75fd228917 in __GI_abort () at abort.c:79
#9  0x00007f75fc0d8025 in g_assertion_message (domain=domain@entry=0x7f75fc17000e "GLib", file=file@entry=0x7f75fc1712f9 "../glib/ghash.c", line=line@entry=493, func=func@entry=0x7f75fc181870 <__func__.25> "g_hash_table_remove_node", 
    message=message@entry=0x7f75a00018b0 "assertion failed: (hash_table->nnodes > 0)") at ../glib/gtestutils.c:3331
#10 0x00007f75fc13f77a in g_assertion_message_expr (domain=domain@entry=0x7f75fc17000e "GLib", file=file@entry=0x7f75fc1712f9 "../glib/ghash.c", line=line@entry=493, func=func@entry=0x7f75fc181870 <__func__.25> "g_hash_table_remove_node", 
    expr=expr@entry=0x7f75fc1712e2 "hash_table->nnodes > 0") at ../glib/gtestutils.c:3357
#11 0x00007f75fc0fecff in g_hash_table_remove_node (hash_table=hash_table@entry=0x56028d8b8360, i=i@entry=0, notify=notify@entry=1) at ../glib/ghash.c:493
#12 0x00007f75fc100a27 in g_hash_table_remove_internal (notify=1, key=0x7f75a0001880, key@entry=0x0, hash_table=0x56028d8b8360) at ../glib/ghash.c:1717
#13 g_hash_table_remove (hash_table=0x56028d8b8360, key=key@entry=0x7f75a0001880) at ../glib/ghash.c:1745
#14 0x00007f75fd151702 in ddc_close_display (dh=0x7f75a0001880) at ddc/ddc_packet_io.c:374
#15 0x00007f75fd192bcc in ddca_close_display (ddca_dh=0x7f75a0001880) at libmain/api_displays.c:587
#16 0x00007f75fee161e6 in BrightnessWorker::ddcSetBrightness (this=0x56028dadb890, value=<optimized out>, display=<optimized out>) at /usr/src/debug/powerdevil-6.1.0/daemon/controllers/ddcutildisplay.cpp:159
#17 0x00007f75fdbd1fbb in QObject::event (this=0x56028dadb890, e=0x56028dbd6970) at /usr/src/debug/qtbase-everywhere-src-6.7.1/src/corelib/kernel/qobject.cpp:1452
#18 0x00007f75fdb8ee20 in QCoreApplication::notifyInternal2 (receiver=0x56028dadb890, event=0x56028dbd6970) at /usr/src/debug/qtbase-everywhere-src-6.7.1/src/corelib/kernel/qcoreapplication.cpp:1134
#19 0x00007f75fdb8ee59 in QCoreApplication::sendEvent (receiver=<optimized out>, event=<optimized out>) at /usr/src/debug/qtbase-everywhere-src-6.7.1/src/corelib/kernel/qcoreapplication.cpp:1575
#20 0x00007f75fdb8f180 in QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x56028dada510) at /usr/src/debug/qtbase-everywhere-src-6.7.1/src/corelib/kernel/qcoreapplication.cpp:1932
#21 0x00007f75fddc2973 in postEventSourceDispatch (s=0x7f75a0000f20) at /usr/src/debug/qtbase-everywhere-src-6.7.1/src/corelib/kernel/qeventdispatcher_glib.cpp:244
#22 0x00007f75fc112740 in g_main_dispatch (context=0x7f75a0000c60) at ../glib/gmain.c:3344
#23 g_main_context_dispatch_unlocked (context=context@entry=0x7f75a0000c60) at ../glib/gmain.c:4152
#24 0x00007f75fc114388 in g_main_context_iterate_unlocked (context=context@entry=0x7f75a0000c60, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../glib/gmain.c:4217
#25 0x00007f75fc114a3c in g_main_context_iteration (context=0x7f75a0000c60, may_block=1) at ../glib/gmain.c:4282
#26 0x00007f75fddc147c in QEventDispatcherGlib::processEvents (this=0x7f75a0000b70, flags=...) at /usr/src/debug/qtbase-everywhere-src-6.7.1/src/corelib/kernel/qeventdispatcher_glib.cpp:394
#27 0x00007f75fdb9959b in QEventLoop::exec (this=0x7f75d55ffaa0, flags=...) at /usr/src/debug/qtbase-everywhere-src-6.7.1/src/corelib/global/qflags.h:34
#28 0x00007f75fdc74ad4 in QThread::exec (this=<optimized out>) at /usr/src/debug/qtbase-everywhere-src-6.7.1/src/corelib/global/qflags.h:74
#29 0x00007f75fdced139 in operator() (__closure=<optimized out>) at /usr/src/debug/qtbase-everywhere-src-6.7.1/src/corelib/thread/qthread_unix.cpp:326
#30 (anonymous namespace)::terminate_on_exception<QThreadPrivate::start(void*)::<lambda()> > (t=...) at /usr/src/debug/qtbase-everywhere-src-6.7.1/src/corelib/thread/qthread_unix.cpp:262
#31 QThreadPrivate::start (arg=0x56028dafe960) at /usr/src/debug/qtbase-everywhere-src-6.7.1/src/corelib/thread/qthread_unix.cpp:285
#32 0x00007f75fd292ba2 in start_thread (arg=<optimized out>) at pthread_create.c:447
#33 0x00007f75fd31400c in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:78

Comment 3 Nate Graham 2024-06-26 20:11:42 UTC

Thanks. Looks like it's crashing in DDC code.

Comment 4 Nate Graham 2024-06-26 20:45:23 UTC

*** Bug 489163 has been marked as a duplicate of this bug. ***

Comment 5 Nate Graham 2024-06-26 21:59:51 UTC

*** Bug 489222 has been marked as a duplicate of this bug. ***

Comment 6 Jakob Petsovits 2024-06-26 22:23:03 UTC

I don't see it in this backtrace, but the one from Bug 489163 has two different threads (Thread 1 and Thread 3) both in BrightnessWorker::ddcSetBrightness(). This made me think - the DDCutilDisplay class's m_brightnessWorkerThread is created per instance, which means that for more than one monitor we'd have more than one brightness setter thread. I think this could be the root of this issue, and would explain why I've never seen the crash in my single-DDC-monitor setup despite months of use.

I'll try tomorrow to refactor it so that the same thread is used across all different monitors, to prevent simultaneous function execution messing up ddcutil's internal (global) state.

Comment 7 Bug Janitor Service 2024-06-27 09:54:09 UTC

A possibly relevant merge request was started @ https://invent.kde.org/plasma/powerdevil/-/merge_requests/390

Comment 8 Pavel Urusov 2024-06-27 09:56:32 UTC

I can confirm that unplugging the 2nd monitor stops the powerdevil from crashing

Comment 9 Jakob Petsovits 2024-07-02 12:06:16 UTC

Git commit 7e1130ffcf7ad667272dabf8345152236a38bf2a by Jakob Petsovits.
Committed on 02/07/2024 at 12:03.
Pushed by jpetso into branch 'master'.

daemon/controllers: Reintroduce a mutex around ddca_open_display2()

ddcutil keeps some global state, and in particular we've seen a
crash in ddc_close_display() related to its open_displays hashmap.

One likely culprit for such a crash is that brightness workers run
on separate threads, one per DDCutilDisplay object, so they
could get executed simultaneously when more than one external
monitor is involved.

A less likely, but still possible culprit is when a DDCutilDisplay
constructor opens a display handle at the same time that a
brightness worker sets the brightness of a different display
on a different thread.

We could look into combining all brightness setter calls into
a single BrightnessWorker that gets shared across DDCutilDisplay
objects, but this would introduce extra complexity and still
wouldn't address the constructor vs. brightness setter issue.

So this commit reintroduces a mutex to isolate all of these usages
from each other. We had one in 5.x, which was removed in 6.0 at my
(in hindsight incorrect) request:
https://invent.kde.org/plasma/powerdevil/-/merge_requests/312#note_865976,
https://invent.kde.org/plasma/powerdevil/-/merge_requests/312#note_867942

M +5 -1 daemon/controllers/ddcutildetector.cpp
M +41 -30 daemon/controllers/ddcutildisplay.cpp
M +3 -1 daemon/controllers/ddcutildisplay.h

https://invent.kde.org/plasma/powerdevil/-/commit/7e1130ffcf7ad667272dabf8345152236a38bf2a

Comment 10 Jakob Petsovits 2024-07-02 12:09:22 UTC

Git commit 209782d50796d8aa2bfe36753c69ed6c77ec5c99 by Jakob Petsovits.
Committed on 02/07/2024 at 12:06.
Pushed by jpetso into branch 'Plasma/6.1'.

daemon/controllers: Reintroduce a mutex around ddca_open_display2()

ddcutil keeps some global state, and in particular we've seen a
crash in ddc_close_display() related to its open_displays hashmap.

(cherry picked from commit 7e1130ffcf7ad667272dabf8345152236a38bf2a)

Co-authored-by: Jakob Petsovits <jpetso@petsovits.com>

M +5 -1 daemon/controllers/ddcutildetector.cpp
M +41 -30 daemon/controllers/ddcutildisplay.cpp
M +3 -1 daemon/controllers/ddcutildisplay.h

https://invent.kde.org/plasma/powerdevil/-/commit/209782d50796d8aa2bfe36753c69ed6c77ec5c99

Comment 11 Jakob Petsovits 2024-07-02 12:13:06 UTC

The merge narrowly missed 6.1.2, so it looks like 6.1.3 in two weeks will be the first release containing this fix.

Comment 12 Nate Graham 2024-07-02 18:50:58 UTC

*** Bug 489630 has been marked as a duplicate of this bug. ***

Comment 13 Eugene Savitsky 2024-07-03 09:19:28 UTC

So, did it made into 6.1.2? Nate changed the Version Fixed In field to 6.1.2.

Comment 14 Jakob Petsovits 2024-07-03 11:15:01 UTC

(In reply to ezh from comment #13)
> So, did it made into 6.1.2? Nate changed the Version Fixed In field to 6.1.2.

The release ended up recreating the powerdevil 6.1.2 release tarball before it got released to the public. So you'll get it anywhere that Plasma 6.1.2 is available.

Comment 15 Pavel Urusov 2024-07-06 10:58:20 UTC

I can confirm that after upgrade to 6.1.2, powerdevil no longer crashes when I try to adjust the brightness of my monitors. The brightness also changes correctly. Thank you

Comment 16 Nicolas Fella 2024-07-07 12:42:08 UTC

*** Bug 489863 has been marked as a duplicate of this bug. ***

Comment 17 Nicolas Fella 2024-07-07 12:42:24 UTC

*** Bug 489721 has been marked as a duplicate of this bug. ***

Comment 18 Nicolas Fella 2024-07-07 12:42:43 UTC

*** Bug 489715 has been marked as a duplicate of this bug. ***

Comment 19 Iyán M. V. 2024-07-08 07:36:59 UTC

After updating to 6.1.2 I still see many ddcutil crashes when attaching my laptop to an external docking station (WD19TBS).

Output of journalctl -p err:

Jul 08 09:17:48 bespin systemd-coredump[9774]: [🡕] Process 9422 (ddcutil) of user 0 dumped core.
                                               
                                               Stack trace of thread 9422:
                                               #0  0x000078ee746d41dd n/a (libc.so.6 + 0x16a1dd)
                                               #1  0x000057dd78414031 strsplit (ddcutil + 0x8b031)
                                               #2  0x000057dd784264ba n/a (ddcutil + 0x9d4ba)
                                               #3  0x000057dd78426778 is_possible_monitor_by_hiddev_name (ddcutil + 0x9d778)
                                               #4  0x000057dd784268a9 check_usb_monitor (ddcutil + 0x9d8a9)
                                               #5  0x000057dd783a4752 main (ddcutil + 0x1b752)
                                               #6  0x000078ee7458fc88 n/a (libc.so.6 + 0x25c88)
                                               #7  0x000078ee7458fd4c __libc_start_main (libc.so.6 + 0x25d4c)
                                               #8  0x000057dd783a4895 _start (ddcutil + 0x1b895)
                                               ELF object binary architecture: AMD x86-64
Jul 08 09:17:48 bespin (udev-worker)[9420]: hiddev3: Process '/usr/bin/ddcutil chkusbmon /dev/usb/hiddev3 -v' terminated by signal SEGV.
Jul 08 09:17:48 bespin (udev-worker)[9420]: hiddev3: Failed to wait for spawned command '/usr/bin/ddcutil chkusbmon /dev/usb/hiddev3 -v': Input/output error
Jul 08 09:17:48 bespin systemd-coredump[9775]: [🡕] Process 9421 (ddcutil) of user 0 dumped core.
                                               
                                               Stack trace of thread 9421:
                                               #0  0x00007c6fd0b941dd n/a (libc.so.6 + 0x16a1dd)
                                               #1  0x00005ee53c609031 strsplit (ddcutil + 0x8b031)
                                               #2  0x00005ee53c61b4ba n/a (ddcutil + 0x9d4ba)
                                               #3  0x00005ee53c61b778 is_possible_monitor_by_hiddev_name (ddcutil + 0x9d778)
                                               #4  0x00005ee53c61b8a9 check_usb_monitor (ddcutil + 0x9d8a9)
                                               #5  0x00005ee53c599752 main (ddcutil + 0x1b752)
                                               #6  0x00007c6fd0a4fc88 n/a (libc.so.6 + 0x25c88)
                                               #7  0x00007c6fd0a4fd4c __libc_start_main (libc.so.6 + 0x25d4c)
                                               #8  0x00005ee53c599895 _start (ddcutil + 0x1b895)
                                               ELF object binary architecture: AMD x86-64
Jul 08 09:17:48 bespin (udev-worker)[9294]: hiddev1: Process '/usr/bin/ddcutil chkusbmon /dev/usb/hiddev1 -v' terminated by signal SEGV.
Jul 08 09:17:48 bespin (udev-worker)[9294]: hiddev1: Failed to wait for spawned command '/usr/bin/ddcutil chkusbmon /dev/usb/hiddev1 -v': Input/output error
Jul 08 09:17:49 bespin systemd-coredump[9828]: [🡕] Process 9802 (ddcutil) of user 0 dumped core.
                                               
                                               Stack trace of thread 9802:
                                               #0  0x000070bcab6a41dd n/a (libc.so.6 + 0x16a1dd)
                                               #1  0x000064e2032bd031 strsplit (ddcutil + 0x8b031)
                                               #2  0x000064e2032cf4ba n/a (ddcutil + 0x9d4ba)
                                               #3  0x000064e2032cf778 is_possible_monitor_by_hiddev_name (ddcutil + 0x9d778)
                                               #4  0x000064e2032cf8a9 check_usb_monitor (ddcutil + 0x9d8a9)
                                               #5  0x000064e20324d752 main (ddcutil + 0x1b752)
                                               #6  0x000070bcab55fc88 n/a (libc.so.6 + 0x25c88)
                                               #7  0x000070bcab55fd4c __libc_start_main (libc.so.6 + 0x25d4c)
                                               #8  0x000064e20324d895 _start (ddcutil + 0x1b895)
                                               ELF object binary architecture: AMD x86-64
Jul 08 09:17:49 bespin (udev-worker)[9427]: hiddev1: Process '/usr/bin/ddcutil chkusbmon /dev/usb/hiddev1 -v' terminated by signal SEGV.
Jul 08 09:17:49 bespin (udev-worker)[9427]: hiddev1: Failed to wait for spawned command '/usr/bin/ddcutil chkusbmon /dev/usb/hiddev1 -v': Input/output error
Jul 08 09:17:49 bespin systemd-coredump[9829]: [🡕] Process 9804 (ddcutil) of user 0 dumped core.

coredumpctl debug 9422:

(gdb) thread apply all backtrace full

Thread 1 (Thread 0x78ee744bbb80 (LWP 9422)):
#0  __strlen_avx2 () at ../sysdeps/x86_64/multiarch/strlen-avx2.S:76
No locals.
#1  0x000057dd78414031 in strsplit (str_to_split=0x0, delims=0x57dd7842faea ":") at util/string_util.c:455
        debug = false
        max_pieces = <optimized out>
        workstruct = <optimized out>
        piecect = <optimized out>
        str_to_split_dup = <optimized out>
        rest = 0x57dd9f453b90 "/dev/usb/hiddev3"
        token = <optimized out>
        result = <optimized out>
        __func__ = <optimized out>
        ndx = <optimized out>
        curpiece = <optimized out>
#2  0x000057dd784264ba in avoid_device_by_usb_interfaces_property_string (interfaces=0x0) at usb/usb_displays.c:346
        debug = false
        pieces = <optimized out>
        avoid = <optimized out>
        ndx = <optimized out>
        __func__ = "avoid_device_by_usb_interfaces_property_string"
#3  0x000057dd78426778 in is_possible_monitor_by_hiddev_name (hiddev_name=hiddev_name@entry=0x57dd9f453b90 "/dev/usb/hiddev3") at usb/usb_displays.c:405
        interfaces = <optimized out>
        debug = false
        devsum = 0x57dd9f466a60
        avoid = false
        result = <optimized out>
        __func__ = "is_possible_monitor_by_hiddev_name"
#4  0x000057dd784268a9 in check_usb_monitor (device_name=0x57dd9f453b90 "/dev/usb/hiddev3") at usb/usb_displays.c:903
        debug = false
        ol = DDCA_OL_VERBOSE
        result = false
        __PRETTY_FUNCTION__ = "check_usb_monitor"
        __func__ = <optimized out>
#5  0x000057dd783a4752 in main (argc=<optimized out>, argv=<optimized out>) at app_ddcutil/main.c:1034
        is_monitor = <optimized out>
        main_debug = false
        s = <optimized out>
        main_rc = 0
        start_time_reported = <optimized out>
        explicit_syslog_level = <optimized out>
        syslog_opened = <optimized out>
        preparse_verbose = <optimized out>
        skip_config = <optimized out>
        parsed_cmd = 0x57dd9f4536c0
        program_start_time = 1720423054
        program_start_time_s = <optimized out>
        new_argv = 0x57dd9f453650
        new_argc = 4
        untokenized_cmd_prefix = 0x0
        configure_fn = 0x0
        preparsed_level = <optimized out>
        bye = <optimized out>
--Type <RET> for more, q to quit, c to continue without paging--c
        errs = <optimized out>
        callopts = 0 '\000'
        values = 0x0
        end_time = 140727784448032
        end_time_s = <optimized out>
        __func__ = "main"
        __PRETTY_FUNCTION__ = "main"

Comment 20 Nate Graham 2024-07-22 20:33:07 UTC

Looks like a different crash. This bug report is about ddc_close_display()