Multi-monitor issues with Debian/Deepin OS

[TheNewJavaman]

I recently installed Deepin OS (based on Debian) and absolutely love it so far. My only issue is pretty big, though. One of my two monitors doesn't have any input, not even black. My BIOS's default graphics device is my graphics card, with my APU force enabled. The monitor that doesn't work is on the APU. When I force my APU to be the default device, my GPU's monitor is disabled. Both work in Windows. Here's some feedback from commands that I've run.

lspci | grep VGA
  00:01.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Kaveri [Radeon R7 Graphics]
  01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Baffin [Radeon RX 460] (rev cf)

xrandr --listproviders
  Providers: number : 2
  Provider 0: id: 0x9c cap: 0xf, Source Output, Sink Output, Source Offload, Sink Offload crtcs: 5 outputs: 3 associated providers: 0 name:AMD Radeon RX 460 Graphics @ 
  pci:0000:01:00.0
  Provider 1: id: 0x46 cap: 0xf, Source Output, Sink Output, Source Offload, Sink Offload crtcs: 4 outputs: 3 associated providers: 0 name:KAVERI @ pci:0000:00:01.0

xrander
  Screen 0: minimum 320 x 200, current 2560 x 1080, maximum 16384 x 16384
  DisplayPort-0 disconnected (normal left inverted right x axis y axis)
  HDMI-A-0 connected primary 2560x1080+0+0 (normal left inverted right x axis y axis) 798mm x 334mm
     2560x1080     59.98*+  74.99  
     1920x1080     74.99    60.00    60.00    50.00    59.94  
     1680x1050     59.88  
     1600x900      60.00  
     1280x1024     75.02    60.02  
     1280x800      59.91  
     1152x864      75.00    59.97  
     1280x720      60.00    50.00    59.94  
     1024x768      75.03    60.00  
     832x624       74.55  
     800x600       75.00    60.32  
     720x576       50.00  
     720x480       60.00    59.94  
     640x480       75.00    60.00    59.94  
  DVI-D-0 disconnected (normal left inverted right x axis y axis)

Any help would be GREATLY appreciated, thank you!

CPU: AMD A10-7850K with R7 APU (Kaveri)
GPU: AMD RX460 (Polaris 11)

 

I also posted this on the Deepin OS forums, this is not the only place that I'm looking for a response.

[AustinJ]

Xorg doesn't get along with multiple devices super well. I am guessing that the monitor that isn't working is plugged into a separate device. Are both monitors plugged into the graphics card or do you have one on the motherboard?

 

Assuming both monitors are plugged into the graphics card... Can you provide the out put of lspci -k, and tell me what each vga device uses for kernel drivers/modules. I may be possible to blacklist the on board graphics driver from loading in the first place. Worse case you are going to have to specify the device in your xorg configs. So for example in your xorg.conf.d folder you have a file called 20-device.conf that would contain:

 

Section "Device"
	Identifier "Card0"
	Driver "amdgpu"
	BusID "PCI:1:0:0"
EndSection

Section "Screen"
	Identifier "Screen0"
	Device "Card0"
	GPUDevice "Card0"
EndSection

 

[TheNewJavaman]

7 hours ago, AustinJ said:

Xorg doesn't get along with multiple devices super well. I am guessing that the monitor that isn't working is plugged into a separate device. Are both monitors plugged into the graphics card or do you have one on the motherboard?

 

I have an ultrawide 1080p monitor at 75hz connected to GPU, as well as a 1080p monitor at 60hz connected to the motherboard.

Quote

Assuming both monitors are plugged into the graphics card... Can you provide the out put of lspci -k, and tell me what each vga device uses for kernel drivers/modules. I may be possible to blacklist the on board graphics driver from loading in the first place.

2

00:01.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Kaveri [Radeon R7 Graphics]
	Subsystem: Gigabyte Technology Co., Ltd Kaveri [Radeon R7 Graphics]
	Kernel driver in use: radeon
	Kernel modules: radeon

01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Baffin [Radeon RX 460] (rev cf)
	Subsystem: XFX Pine Group Inc. Baffin [Radeon RX 460]
	Kernel driver in use: amdgpu
	Kernel modules: amdgpu

Quote

Worse case you are going to have to specify the device in your xorg configs. So for example in your xorg.conf.d folder you have a file called 20-device.conf that would contain:

 

Section "Device"
	Identifier "Card0"
	Driver "amdgpu"
	BusID "PCI:1:0:0"
EndSection

Section "Screen"
	Identifier "Screen0"
	Device "Card0"
	GPUDevice "Card0"
EndSection

 

I'll try this out next. Thank you for the information!

 

Edit: I tried different variations of your example 20-device.conf file, and now have the Deepin OS startup logo on one side. We're definitely closer!

[AustinJ]

Are you able to plug both into the card? I don't have very good experience with using motherboard inputs.

 

I assume you have no interest for on board graphics. So you could probably blacklist that. I am not sure how that'll make the motherboard output respond however. To blacklist create /etc/modprobe.d/radeon.conf

blacklist radeon

Once that file is created you'll need to run the following commands to update things:

sudo depmod -ae
sudo update-initramfs -u

I haven't been a Debian guy for a while so no clue how you do somethings over there, but I got those commands from here: https://wiki.debian.org/KernelModuleBlacklisting

 

You'll need to reboot for the blacklist to take effect. The 20-device.conf will no longer be needed since there won't be multiple devices present, but it won't hurt to have. If you have any troubles try removing it.