Mesa10.2.8/10.3 and Kabini: tearing :-(

Hi *

I'm developing small distro for MythTV appliance (minimyth2.linuxd.org).

Currently I done some tests with kernel3.16.3, libdrm 2.4.58, 
Xorg1.16.1, Mesa10.2.8/10.3, xorg-f86-ati 7.5.

On Brazos (HD6310) all works quite well (well - only occasional frame 
drops).

However with Kabini (HD8210) I have unpleasant tearing on video playback.

I done some tests and it looks like tearing is only on interlaced 
content and only on radeonsi.
r600 works perfect for all cases.
radeonsi however works OK only for progressive content.
For interlaced content radeonsi has tearing.

As progressive content works OK - for me it looks like Vsync works OK 
and bug is in radeonsi deinterlacer.

I'm wonder - are there any knobs in Mesa config where I can try to play 
with?

Or maybe should I fill bug for Mesa?

thx in advance!