AMD Dual Graphics (Crossfire) doesn't work, FGLRX doesn't see card 2, although generic radeon does.

I have an AMD A10 7850k APU with R7 graphics and an MSI R7 250 graphics card I just installed. Before installing, I was running the fglrx drivers without the graphics card just fine. I uninstalled the fglrx drivers, rebooted to make sure the generic radeon drivers were working, shut down, and installed the graphics card. Per the motherboard’s manual, I installed the graphics card, set it as the initial display in BIOS, adjusted the BIOS by setting the APU to forced and setting the UMA buffer to 2gb (the manual specifies above 512k), and plugged the monitor into the new graphics card, again as the manual specified. I rebooted into Leap and everything seemed to be working fine. The Hardware Info module in Yast showed both the APU graphics and the new graphics card as it should. Having verified this, I installed fglrx from the fglrx repository (which I had been using successfully before), and rebooted. Disaster – the computer booted fine, it told me X had started, but X never actually came up. After some thought, I went into BIOS, set the APU as the initial display, plugged the monitor into the APU, and rebooted. This time X did come up. I verified fglrx was running and I verified in HW Info that both the APU and the graphics card were there, but when I went into Catalyst, there was no option to enable dual graphics as there was supposed to be and the information tab showed only one graphics adapter - the APU.

In a nutshell, then, it appears that fglrx does not see the graphics card, although it is there and the generic radeon driver sees it fine. Could it be that aticonfig didn’t properly run and see the graphics card? Is there a configuration file I can modify by hand to get fglrx to see the graphics card?

I’d really appreciate any help.


A little more information:

aticonfig --lsa returns the following:

    1. 00:01.0 AMD Radeon™ R7 Graphics
    2. 01:00.0 AMD Radeon R7 200 Series
    • Default adapter

According to the AMD web site, the Radeon R7 250 (which is card 1) is the recommended card for dual graphics with the A10 7850k (the APU, card 0). However, aticonfig --lscc (show Crossfire candidates) returns:

Master adapter: 0. 00:01.0 AMD Radeon™ R7 Graphics
Candidates: none

The Xorg.conf file that was generated by the installation of fglrx is as follows:

Section "ServerLayout"
    Identifier     "aticonfig Layout"
    Screen      0  "aticonfig-Screen[0]-0" 0 0

Section "Module"

Section "Monitor"
    Identifier   "aticonfig-Monitor[0]-0"
    Option        "VendorName" "ATI Proprietary Driver"
    Option        "ModelName" "Generic Autodetecting Monitor"
    Option        "DPMS" "true"

Section "Device"
    Identifier  "aticonfig-Device[0]-0"
    Driver      "fglrx"
    BusID       "PCI:0:1:0"

Section "Screen"
    Identifier "aticonfig-Screen[0]-0"
    Device     "aticonfig-Device[0]-0"
    Monitor    "aticonfig-Monitor[0]-0"
    DefaultDepth     24
    SubSection "Display"
        Viewport   0 0
        Depth     24

I have made progress. By running aticonfig --adapter=all --initial --desktop-setup=single, I managed to get both adapters recognized. With the add-in graphics card in the first device block, I can run the monitor from the adapter rather than the APU. Getting Crossfire to work is another issue. Running the following two commands, restarting X between each one, created a multiple device chain and presumably started it.

aticonfig --adapter=1,0 --cfa
aticonfig --adapter=1,0 --crossfire=on

. However, the message returned by the second command casts doubt

Crossfire chain(s) enabled
CrossFire does not support on this platform
Warning: X needs to be restarted before CrossFire changes take effect.

. The non-support message is disturbing, but AMD’s web site says dual graphics are supported by both the APU and the R7 250 card and my motherboard manual says the motherboard supports it. So after a reboot, I run aticonfig --lsch and am shown the following which makes me happy:

Multiple GPU chain for adapter 1, status: Crossfire is enabled  
  1. 01:00.0 AMD Radeon R7 200 Series
  0. 00:01.0 AMD Radeon(TM) R7 Graphics

. But, on the other hand, aticonfig --lscs tells me it is disabled. Upshot, I don’t know now whether it is working or not.