webcam debugging: 0bda:5716 Realtek Semiconductor Corp.

I have some problems with the webcam 0bda:5716 Realtek Semiconductor Corp. run via the uvcvideo driver on opensuse 13.1 (on a dell xps12 laptop)
The camera runs under luvcview but no other application. After some time I figured out that the camera also works with guvcview when I specify the -r 2 (use read system call instead of mmap). Unfortunately, this leaves kamoso and skype still with a black screen. Supposedly they still use mmap for accessing the camera. Is there a way to get mmap working or to force other application also going the read-system call way? It would be preferable to get mmap working as already with a 640x480 resolution video playback shows artifacts.

Any help appreciated.

Best, Stevean