Arch Linux

scorpius2k1

Member

Registered: 2021-04-11

Posts: 2

No Variable Refresh Rate/FreeSync option on Supported Hardware?

Greetings all! I am having a weird issue and am not able to figure out why I cannot enable Variable Refresh Rate/FreeSync option on my supported hardware.
Latest stock kernel in use on Arch Linux as of this post: 5.11.11-arch1-1

I am using the free xf86-video-amdgpu driver with Xorg / XFCE, and monitor is hooked into DisplayPort 1.4 on my GPU.

When I run

xrandr --props

I don't see any line that says 'vrr_capable'. I have a Radeon RX580 GPU and a Samsung C32HG70 FreeSync monitor with FreeSync option enabled in the settings. I also have Option "VariableRefresh" "true" on my '/etc/X11/xorg.conf.d/20-amdgpu.conf
' file. I have read through the Wiki page https://wiki.archlinux.org/index.php/Va … _on_AMDGPU

My C32HG70 monitor is also officially supported with AMD (https://www.amd.com/en/products/freesync-monitors)

Any ideas what is going on here? Thanks for any input.

Here is my '20-amdgpu.conf' config file:

Section "Device"
        Identifier "AMD"
        Driver "amdgpu"
        Option "TearFree" "false"
        Option "DRI" "3"
        Option "VariableRefresh" "true"
EndSection

Section "Screen"
        Identifier "Samsung C32HG70"
        Monitor "LCD"
        DefaultDepth 24
EndSection

Output of

xrandr --props

DisplayPort-0 connected primary 2560x1440+0+0 (normal left inverted right x axis y axis) 697mm x 392mm
	EDID: 
		00ffffffffffff004c2d140e57325743
		32300104b54627783bef35ad5044aa27
		0f5054bfef80714f810081c081809500
		a9c0b300010122e50050a0a067500820
		f80cb9882100001a000000fd003090df
		df3b010a202020202020000000fc0043
		3332484737780a2020202020000000ff
		0048345a4e3430313138310a2020011f
		02032ef148901f041303123f40230907
		0783010000e305c0006d1a0000020f30
		90000473175a1ee6060501735a17565e
		00a0a0a0295030203500b9882100001a
		023a801871382d40582c4500b9882100
		001e5aa000a0a0a0465030203500b988
		2100001a6fc200a0a0a0555030203500
		b9882100001a00000000000000000037
	TearFree: off 
		supported: off, on, auto
	subconnector: Native 
		supported: Unknown, VGA, DVI-D, HDMI, DP, Wireless, Native
	dither: off 
		supported: off, on
	audio: auto 
		supported: off, on, auto
	scaling mode: None 
		supported: None, Full, Center, Full aspect
	underscan vborder: 0 
		range: (0, 128)
	underscan hborder: 0 
		range: (0, 128)
	underscan: off 
		supported: off, on, auto
	coherent: 1 
		range: (0, 1)
	link-status: Good 
		supported: Good, Bad
	CONNECTOR_ID: 52 
		supported: 52
	non-desktop: 0 
		range: (0, 1)
   2560x1440    144.00*+ 120.00    99.95    59.95  
   1920x1080    120.00   100.00   119.88    60.00    50.00    59.94  
   1680x1050     59.95  
   1600x900      60.00  
   1280x1024     75.02    60.02  
   1440x900      59.89  
   1280x800      59.81  
   1152x864      75.00  
   1280x720      60.00    50.00    59.94  
   1024x768      75.03    70.07    60.00  
   832x624       74.55  
   800x600       72.19    75.00    60.32    56.25  
   720x576       50.00  
   720x480       60.00    59.94  
   640x480       75.00    72.81    66.67    60.00    59.94  
   720x400       70.08

Last edited by scorpius2k1 (2021-04-11 20:31:02)

scorpius2k1

Member

Registered: 2021-04-11

Posts: 2

Re: No Variable Refresh Rate/FreeSync option on Supported Hardware?

I solved my own issue, hopefully the solution might help others. This was a bit of a rare case, but I had a kernel parameter in my grub.cfg file I had used with an older gpu for compatibility with amdgpu driver. This also disabled things like FreeSync, DisplayPort Multi-Stream Transport (MST) support, at a minimum.

amdgpu.dc=0

https://www.kernel.org/doc/html/latest/ … pu-dc.html

After that was removed, everything is working as expected.

Last edited by scorpius2k1 (2021-04-11 23:13:15)