When I close the lid of my Acer Nitro laptop, I see this in my journal:
systemd-logind[628]: Lid closed.
systemd-logind[628]: Suspending...
...
systemd-sleep[2396]: Entering sleep state 'suspend'...
kernel: PM: suspend entry (deep)
kernel: Filesystems sync: 0.004 seconds
kernel: Freezing user space processes
kernel: Freezing user space processes failed after 20.002 seconds (1 tasks refusing to freeze, wq_busy=0):
kernel: task:(sd-bright) state:D stack:0 pid:2229 ppid:628 flags:0x00000006
kernel: Call Trace:
kernel: <TASK>
kernel: __schedule+0x2aa/0x610
kernel: schedule+0x63/0x110
kernel: schedule_preempt_disabled+0x15/0x30
kernel: __mutex_lock.constprop.0+0x3f8/0x7a0
kernel: __mutex_lock_slowpath+0x13/0x20
kernel: mutex_lock+0x3c/0x50
kernel: backlight_device_set_brightness+0x35/0x140
kernel: brightness_store+0x75/0x90
kernel: dev_attr_store+0x17/0x40
kernel: sysfs_kf_write+0x3e/0x60
kernel: kernfs_fop_write_iter+0x133/0x210
kernel: vfs_write+0x251/0x410
kernel: ksys_write+0x73/0x100
kernel: __x64_sys_write+0x19/0x30
kernel: do_syscall_64+0x5b/0x90
kernel: ? __x64_sys_fcntl+0xba/0xe0
kernel: ? exit_to_user_mode_prepare+0x30/0xb0
kernel: ? syscall_exit_to_user_mode+0x29/0x50
kernel: ? do_syscall_64+0x67/0x90
kernel: ? do_user_addr_fault+0x1bb/0x620
kernel: ? exit_to_user_mode_prepare+0x30/0xb0
kernel: ? irqentry_exit_to_user_mode+0x9/0x20
kernel: ? irqentry_exit+0x43/0x50
kernel: ? exc_page_fault+0x91/0x1b0
kernel: entry_SYSCALL_64_after_hwframe+0x72/0xdc
kernel: RIP: 0033:0x7f82d990ba1f
kernel: RSP: 002b:00007ffe7b9afc10 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
kernel: RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f82d990ba1f
kernel: RDX: 0000000000000004 RSI: 00007ffe7b9afcf0 RDI: 0000000000000004
kernel: RBP: 00007ffe7b9afcf0 R08: 0000000000000000 R09: 00007f82d99f6c80
kernel: R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000004
kernel: R13: 0000561cdb4a95b0 R14: 0000000000000004 R15: 00007f82d99f2d00
kernel: </TASK>
I cannot find sd-bright in the list from systemctl command.
Also dpkg -S sd-bright yields nothing.
OS: Ubuntu 23.04
kernel: 6.2.0-32-generic
sd-brightisn't an installed program or a package or a service. It's a kernel task/call, and is embedded in the Linux kernel. Your system attempted to enter suspend, and during the attempt to execute the set of tasks to go into suspended mode, the kernel had a failed task which caused the kernel dump/error that you see here. Unfortunately, there's nothing we can do to fix this, you need to file this report of an issue against the linux package on Launchpad (see https://askubuntu.com/questions/5121/how-do-i-report-a-bug) – Thomas Ward Sep 10 '23 at 04:01backlight_device_set_brightness+0x35/0x140in the traceback, one may infer the context of the ptoblrm. – waltinator Sep 10 '23 at 16:50