When calling something like
echo "low" > /sys/class/drm/card0/device/power_profile
my display flickers a single time. This is okay-ish, but on Microsoft Windows the clock changes do not cause such a flicker. There has to be some kind of trick to achieve that and it would be great if this would work an Linux, too.
Tested on vanilla kernel 2.6.39 with libdrm 2.4.26 and xf86-video-ati 6.14.2.
I have this behavior too.
I have this flickering issue too on my HD8650.
But not only moving to high to low profile. It flickers low to high profile too! This doesn't let us use "dynpm"...
Using Kernel 3.3.5 with mesa/radeon/drm trunk.