Comment 10 for bug 1488426

lpuser (lpuser) wrote :

Your hunch was correct.
I plugged in USB devices in all USB ports and the issue went away.
Then I started to unplug them one by one and I noticed that the problem is related only to one of the 3 external USB ports.
As soon as I unplug the device from that USB port kworker and ksoftirqd will instantly start to abuse the CPU.

USB devices:

$ lsusb
Bus 004 Device 006: ID 0cf3:e005 Atheros Communications, Inc.
Bus 004 Device 002: ID 0438:7900 Advanced Micro Devices, Inc.
Bus 004 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 004: ID 06cb:75bf Synaptics, Inc.
Bus 003 Device 003: ID 0bda:0129 Realtek Semiconductor Corp. RTS5129 Card Reader Controller
Bus 003 Device 002: ID 0438:7900 Advanced Micro Devices, Inc.
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 002: ID 0bda:5684 Realtek Semiconductor Corp.
Bus 001 Device 008: ID 0458:003a KYE Systems Corp. (Mouse Systems) NetScroll+ Mini Traveler / Genius NetScroll 120 <== I connected a mouse to the USB port that I mentioned earlier
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub