Comment 41 for bug 1488426

Yu Lou (louyu1999) wrote :

The bug also affects me on ubuntu 18.10 with the latest kernel (Linux 4.18.0-15-generic #16pop2-Ubuntu SMP Fri Feb 22 17:07:14 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux)

I'm using DELL XPS 15 with a usb type-c hub produced by Ugreen.

Here is the perf report:

Samples: 43K of event 'cycles:ppp', Event count (approx.): 39008781644
  Children Self Command Shared Object Symbol
+ 88.47% 0.00% kworker/4:2+pm [kernel.kallsyms] [k] ret_from_fork
+ 88.47% 0.00% kworker/4:2+pm [kernel.kallsyms] [k] kthread
+ 88.47% 0.01% kworker/4:2+pm [kernel.kallsyms] [k] worker_thread
+ 88.45% 0.07% kworker/4:2+pm [kernel.kallsyms] [k] process_one_work
+ 88.04% 0.02% kworker/4:2+pm [kernel.kallsyms] [k] rpm_idle
+ 87.94% 0.03% kworker/4:2+pm [kernel.kallsyms] [k] pm_runtime_work
+ 87.85% 0.04% kworker/4:2+pm [kernel.kallsyms] [k] rpm_suspend
+ 87.81% 0.04% kworker/4:2+pm [kernel.kallsyms] [k] __rpm_callback
+ 87.79% 0.01% kworker/4:2+pm [kernel.kallsyms] [k] usb_runtime_idle
+ 87.75% 0.01% kworker/4:2+pm [kernel.kallsyms] [k] __pm_runtime_suspend
+ 87.64% 0.02% kworker/4:2+pm [kernel.kallsyms] [k] rpm_callback
+ 87.57% 0.03% kworker/4:2+pm [kernel.kallsyms] [k] usb_runtime_suspend
+ 87.50% 0.03% kworker/4:2+pm [kernel.kallsyms] [k] usb_suspend_both
+ 85.34% 0.13% kworker/4:2+pm [kernel.kallsyms] [k] usb_control_msg
+ 84.75% 0.13% kworker/4:2+pm [kernel.kallsyms] [k] usb_start_wait_urb
+ 82.66% 0.15% kworker/4:2+pm [kernel.kallsyms] [k] usb_submit_urb
+ 82.42% 0.23% kworker/4:2+pm [kernel.kallsyms] [k] usb_hcd_submit_urb
+ 79.45% 79.23% kworker/4:2+pm [kernel.kallsyms] [k] xhci_hub_control
+ 75.52% 0.13% kworker/4:2+pm [kernel.kallsyms] [k] hub_suspend
+ 74.18% 0.03% kworker/4:2+pm [kernel.kallsyms] [k] set_port_feature
+ 11.83% 0.03% kworker/4:2+pm [kernel.kallsyms] [k] usb_resume_interface.isra.12
+ 11.82% 0.01% kworker/4:2+pm [kernel.kallsyms] [k] hub_resume
+ 11.80% 0.14% kworker/4:2+pm [kernel.kallsyms] [k] hub_activate
+ 11.38% 0.08% kworker/4:2+pm [kernel.kallsyms] [k] hub_ext_port_status
+ 5.78% 0.00% ksoftirqd/4 [kernel.kallsyms] [k] ret_from_fork
+ 5.78% 0.00% ksoftirqd/4 [kernel.kallsyms] [k] kthread
+ 5.48% 0.35% ksoftirqd/4 [kernel.kallsyms] [k] smpboot_thread_fn