On 10/10/17 07:50 PM, Anton Ivanov wrote:
Package: xserver-xorg-video-radeon
Version: 1:7.8.0-1+b1
Severity: important
Dear Maintainer,
Radeon (and amdgpu for that matter) in stretch no longer match frames
to vsync correctly. This is observable with vdpau, opengl and plain
xvideo.
This used to work correctly in jessie so this is a recent regression.
This is also observable in both full screen and windowed mode. The
bottom ~5-10% of the picture updates on the wrong vsycn which is
clearly visible especially in action sequences and animation.
Tested with vlc, mplayer, xine and other software in a variety of
output modes. I think I have eliminated other possible common factors
leaving the video driver (and/or firmware) the most likely culprit.
The only possibilities for reliably avoiding tearing in Xorg have always
been:
1. Using a compositing manager which uses OpenGL for rendering
2. Running an application in fullscreen, using page flipping (i.e. the
application must use something like OpenGL / VDPAU / VA-API / ... for
rendering / presentation, but not something like XVideo or even pure
X11)
3. Enabling TearFree
Note that 1.+2. are not sufficient when using rotation or other
transforms via the RandR extension.
Does your setup fall under any of these cases? If not, you may just have
gotten lucky before.