Created attachment 278441 [details]
Complete bugreport as reported originally against the usbtv repository.

UsbTV kernel driver causes complete system freeze on Armbian OrangePi PC kernel 4.14

How to reproduce:

- Let's have a Allwinner H3 chip based single board computer (e.g. Orange PI PC )
- Use most recent Armbian with kernel 4.14
- Let's have UTV007 (Fushicai) based USB video grabber
- Use the kernel V4L2 driver 'usbtv' from the default kernel
- Assume the UTV007 device is /dev/video0
- Open the /dev/video0 in VLC (or any other tool using the V4L usbtv driver; actually it is enough to cat /dev/video0>/dev/null)

What happens:

The system becomes unresponsive and later freezes completely with the "" message in syslog. The process using the /dev/video0 starts to eat all system resources 390%load (on 4 cpu system) before the log message appears.

What is expected:

The system should process the video with average load approx 30% (tested with other USB grabbers and USB cameras).

System info:

'uname -a': Linux orangepipc 4.14.65-sunxi #68 SMP Tue Aug 21 19:57:06 CEST 2018 armv7l armv7l armv7l GNU/Linux

Observation:

The bug does not show on "Linux mylaptop 4.10.0-42-generic #46~16.04.1-Ubuntu SMP Mon Dec 4 15:57:59 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux". Wich may be however caused by the power of the laptop itself.