How to enable Radeon Pro Duo with mesa

[Lvzhihong (ReJohn)]

> What are you trying to do?  A large desktop spread across both chips?
> Use the chips independently?  There is no support for crossfire on Linux.  If you want to use a desktop across multiple chips or select which chip is used for rendering, you can use xrandr and the prime support in X:
> https://wiki.archlinux.org/index.php/PRIME

I want to select one chip to render for my application. And now I know how to select which chip: after set env DRI_PRIME=1 , the second chip will be used. But there is another problem: the second chip's performance is very bad , only 1/4 of the first chip. 

xrandr --listproviders:
Providers: number : 2
Provider 0: id: 0x7f cap: 0x9, Source Output, Sink Offload crtcs: 6 outputs: 4 associated providers: 1 name:AMD Radeon (TM) Pro WX 7100 Graphics @ pci:000d:33:00.0 Provider 1: id: 0x45 cap: 0x6, Sink Output, Source Offload crtcs: 6 outputs: 0 associated providers: 1 name:AMD Radeon (TM) Pro WX 7100 Graphics @ pci:000d:34:00.0

Here is the results of running glxgears: 
DRI_PRIME=1 vblank_mode=0  glxgears
ATTENTION: default value of option vblank_mode overridden by environment.
5486 frames in 5.0 seconds = 1097.200 FPS

DRI_PRIME=0 vblank_mode=0  glxgears
ATTENTION: default value of option vblank_mode overridden by environment.
19846 frames in 5.0 seconds = 3969.058 FPS

How to resolve this?


> On Wed, Mar 14, 2018 at 5:41 AM, Lvzhihong (ReJohn) <lvzhihong1 at huawei.com> wrote:
> Hi All ,
>
> Does mesa support Radeon Pro Duo? I don’t know how to configure 
> xorg.conf to use two WX7100 card of DUO , and now I can only use the first card of DUO.
>
> What are you trying to do?  A large desktop spread across both chips?
> Use the chips independently?  There is no support for crossfire on Linux.  If you want to use a desktop across multiple chips or select which chip is used for rendering, you can use xrandr and the prime support in X:
> https://wiki.archlinux.org/index.php/PRIME
>
> Alex


>
> Installed software packages: xserver-xorg  xfce4  xinit
>
> Mesa version: 17.2.8  kernel version: 4.15
>
>
>
> Pci information:
>
> 000d:31:00.0 PCI bridge: PLX Technology, Inc. PEX 8747 48-Lane, 5-Port 
> PCI Express Gen 3 (8.0 GT/s) Switch (rev ca)
>
> 000d:32:08.0 PCI bridge: PLX Technology, Inc. PEX 8747 48-Lane, 5-Port 
> PCI Express Gen 3 (8.0 GT/s) Switch (rev ca)
>
> 000d:32:10.0 PCI bridge: PLX Technology, Inc. PEX 8747 48-Lane, 5-Port 
> PCI Express Gen 3 (8.0 GT/s) Switch (rev ca)
>
> 000d:33:00.0 VGA compatible controller: Advanced Micro Devices, Inc.
> [AMD/ATI] Ellesmere [Radeon Pro WX 7100]
>
> 000d:33:00.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] 
> Device
> aaf0
>
> 000d:34:00.0 Display controller: Advanced Micro Devices, Inc. 
> [AMD/ATI] Ellesmere [Radeon Pro WX 7100]
>
>
>
> My xorg.conf:
>
> Section "Device"
>
>        Identifier "AMD"
>
>        Driver "amdgpu"
>
>        BusID "pci:51 at 13:00:00"
>
> EndSection
>
> Section "Monitor"
>
>         Identifier "monitor0"
>
>         Option "enable" "true"
>
> EndSection
>
> Section "Screen"
>
>         Identifier "screen0"
>
>         Device "AMD"
>
>         Monitor "monitor0"
>
>         DefaultDepth 24
>
>         SubSection "Display"
>
>                 Depth 24
>
>         EndSubSection
>
> EndSection
>
>
>
> I use “startx” to start desktop , and only the first WX7100(PCI Bus ID:
> 000d:33:00.0) being used , the second WX7100(PCI Bus ID: 000d:34:00.0) 
> has no load .
>
>          Even if I set BusID as "pci:52 at 13:00:00" (the second WX7100), 
> it still only the first WX7100 being used.
>
>
>
>       So , How to enable Radeon Pro Duo with opensource driver , does 
> my xorg.conf is wrong or mesa doesn’t support Radeon Pro Duo?
>
>
>
>
>
>
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