Mobility Radeon HD 4530/4570/545v: flicker in 1920x1080

[Christian König]

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 at 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 at half:~$ xrandr --output VGA-0 --mode 1600x1200
>   pavel at half:~$ xrandr --output VGA-0 --mode 1920x1080
>   pavel at 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