(In reply to Christian König from comment #13)

> 
> Page flipping operations are tear free, so what we see here is that without
> deinterlacing the graphics stack uses page flipping and with deinterlacing
> it uses glamor with of course results in badly tearing of the video.

Indeed - infrastructure for flipping seems to be ready:

[837858.379] (II) RADEON(0): KMS Pageflipping: enabled
[837858.379] (II) RADEON(0): SwapBuffers wait for vsync: enabled
[837858.389] (II) RADEON(0): Output HDMI-0 using monitor section Monitor1

> 
> The question is why the heck do we fallback to a copy operation with glamor
> when deinterlacing is enabled? 

If You believe we should do some tests with added debug outputs - I'm more than
happy to do so :-)