On 31.10.2015 21:13, Pavel Machek wrote:

Hi!

4.3-rc7 kernel, graphics works reasonably well in 1600x1200 mode. But
my monitor is native 1920x1080, so that mode looks pretty ugly on
screen. If I go to 1920x1080, I see colored horizontal lines (often
black) as soon as there's graphics activity.

pavel@half:~$ xrandr
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 8192 x 8192
VGA-0 connected 1920x1080+0+0 (normal left inverted right x axis y
axis) 478mm x 268mm
    1920x1080     60.00*+
       1600x1200     60.00
          1680x1050     59.95
	    1280x1024     75.02    60.02
	       1440x900      59.89
	          1024x768      75.08    60.00
		     800x600       75.00    60.32
		        640x480       75.00    60.00
			   720x400       70.08
  pavel@half:~$ xrandr --output VGA-0 --mode 1600x1200
  pavel@half:~$ xrandr --output VGA-0 --mode 1920x1080
  pavel@half:~$ xrandr --output VGA-0 --mode 1600x1200
			

This is Acer notebook,

01:00.0 VGA compatible controller: Advanced Micro Devices,
Inc. [AMD/ATI] RV710/M92 [Mobility Radeon HD 4530/4570/545v]

Ouch, and power consumption seems to be 8W too high. (25W instead of
17W), I believe it started when I added radeon firmware, but will
check. It does not go lower even when I switch to text console.

Any ideas?

Alex probably knows more about this, but it sounds like problems with 
switching the memory clocks on 3D load.

Try to disable power management completely with radeon.dpm=0 on the 
kernel command line or nailing the hardware at a specific power level 
using sysfs.

Power consumption would be totally awkward, but it should help nailing 
down the problem.

Regards,
Christian.

									Pavel