AMDGPU

Prerequisites

Firmware

It is necessary to install the proper firmware (or microcode) for your card. Firmware files are provided by sys-kernel/linux-firmware. Make sure you have all necessary files for your hardware in your configuration file if you use the savedconfig USE flag.

The firmware files installed this way will be incorporated into the kernel.

Kernel

Set the following kernel options for the graphic chipsets mentioned above:

Processor type and features  --->
    [*] MTRR (Memory Type Range Register) support (''CONFIG_MTRR'')
Device Drivers  --->
    Graphics support  --->
        <*/M> Direct Rendering Manager (XFree86 4.1.0 and higher DRI support) ---> (''DRM_FBDEV_EMULATION'')
              [*]   Enable legacy fbdev support for your modesetting driver
        <   > ATI Radeon
        <M/*> AMD GPU
              [ /*] Enable amdgpu support for SI parts (''DRM_AMDGPU_SI'')
                    (only needed for Southern Islands GPUs with the amdgpu driver)
              [ /*] Enable amdgpu support for CIK parts (''DRM_AMDGPU_CIK'')
                    (only needed for Sea Islands GPUs with the amdgpu driver)
              ACP (Audio CoProcessor) Configuration  ---> 
                  [*] Enable AMD Audio CoProcessor IP support (''CONFIG_DRM_AMD_ACP'')
                        (only needed for APUs)
              Display Engine Configuration  --->
                  [*] AMD DC - Enable new display engine (''DRM_AMD_DC'')
                  [ /*] DC support for Polaris and older ASICs
                        (only needed for Polaris, Carrizo, Tonga, Bonaire, Hawaii)
                  [ /*] AMD FBC - Enable Frame Buffer Compression
                  [ /*] DCN 1.0 Raven family
                        (only needed for Vega RX as part of Raven Ridge APUs)
                  [ /*] DCN 3.0 family
                        (only needed for NAVI21/Sienna Cichlid GPUs with the amdgpu driver)
        <*/M> HSA kernel driver for AMD GPU devices (''HSA_AMD'')
    <*/M> Sound card support  --->
        <*/M> Advanced Linux Sound Architecture  --->
            [*]   PCI sound devices ---> (''CONFIG_SND_PCI'')
                  HD-Audio  --->
                      <*> HD Audio PCI (''CONFIG_SND_HDA_INTEL'')
                      [*] Support initialization patch loading for HD-audio (''CONFIG_SND_HDA_PATCH_LOADER'')
                      <*> whatever audio codec your soundcard needs
                      <*> Build HDMI/DisplayPort HD-audio codec support (''CONFIG_SND_HDA_CODEC_HDMI'')
                  (2048) Pre-allocated buffer size for HD-audio driver (''CONFIG_SND_HDA_PREALLOC_SIZE'')

The options from the Sound card support menu need only to be set if the card supports HDMI or DisplayPort audio and you want to use it. On newer kernels where Enable AMD Audio CoProcessor IP support appears, that should also be set.

AMDGPU with Display Core was first implemented for VEGA10 (GCN5.0) and RAVEN (with DCN 1.0) GPUs/APUs. Kernels before version 4.17 have (experimental) DC support for older cards (GCN1.1 and newer) via command line option amdgpu.dc=1, which may work better than the older radeon kernel module. Likewise, if DC needs to be disabled for any particular reason, option amdgpu.dc=0 can be used on the kernel command line.

See the radeon article for more details about using HDMI/DisplayPort audio.

Device Drivers  --->
    Generic Driver Options  --->
        -*- Userspace firmware loading support
        [*] Include in-kernel firmware blobs in kernel binary 
            (amdgpu/<YOUR-MODEL>.bin or radeon/<YOUR-MODEL>.bin) (''CONFIG_EXTRA_FIRMWARE'')
            (/lib/firmware) Firmware blobs root directory

Device Drivers  --->
    Generic Driver Options  --->
        Firmware loader --->
          -*- Firmware loading facility
          (amdgpu/<YOUR-MODEL>.bin or radeon/<YOUR-MODEL>.bin) Build named firmware blobs into the kernel binary
          (/lib/firmware) Firmware blobs root directory

X11 driver

<syntaxhighlight lang="bash">VIDEO_CARDS="amdgpu radeonsi"</syntaxhighlight>

dpm

In most cases since Linux 3.13 dpm is the default power management method. Unlike with dynpm and profile methods enabling or disabling dpm must be done via kernel command line. Users who have GPUs older than HD5000 -series may need to add radeon.dpm=1 on kernel command-line to enable dpm.

In most cases just enabling dpm is enough but there are some tunable settings. dpm has three main modes of operating: battery, balanced and performance. The names are quite self-explanatory. To set the GPU to most performant mode the following command is needed to run:

Even if GPU is set to performance -mode it does not mean that the GPU is running with highest clockspeeds at all the time. This is the normal and intended way how dpm works. If it is desirable to run the GPU at the highest speeds all the time, even if there is no actual load, users can then run following command:

This manually overrides dpm's own bahaviour. This is however mainly intended for testing purposes but may also be useful when doing GPU benchmanks.

To give control back to dpm following command is needed to run:

Debug tools

It might be helpful to install the package x11-apps/mesa-progs, which provides the packages glxgears and glxinfo.

Test, if a discrete graphics card is in use

First make sure that the kernel was compiled with the following settings:

Device Drivers --->
    Graphics support  --->
        -*- VGA Arbitration (CONFIG_VGA_ARB)
        [*] Laptop Hybrid Graphics - GPU switching support (CONFIG_VGA_SWITCHEROO)

Check, if the discrete graphics card was recognized:

[...]
01:00.0 Display controller: Advanced Micro Devices, Inc. [AMD/ATI] Mars [Radeon HD 8670A/8670M/8750M]
        Subsystem: Lenovo Mars [Radeon HD 8670A/8670M/8750M]
        Kernel driver in use: radeon
[...]

After that. Make sure that the path /sys/kernel/debug/ was mounted successfully:

TARGET            SOURCE  FSTYPE  OPTIONS
/sys/kernel/debug debugfs debugfs rw,nosuid,nodev,noexec,relatime

Then, check, if the driver vga_switcheroo was loaded successfully and can output values:

0:DIS: :DynOff:0000:01:00.0
1:IGD:+:Pwr:0000:00:02.0

This output has the following structure^[9]:

DIS represents the discrete graphics card, which is inactive, but currently disconnected (DynOff).
IGD is the integrated graphics card, which is active (+) and is currently in use (Pwr).

The status can be manipulated using the following command:

Replace <some_parameter> with one of the following paramters^[10]:

By using the environment variable DRI_PRIME=1, one can use the discrete graphics card individually:

This opens an X window with rotating gears.

Let it run in the background and check, vga_switcheroo again:

0:DIS: :DynPwr:0000:01:00.0
1:IGD:+:Pwr:0000:00:02.0

Another indicator is to check the temperature sensors. This requires sys-apps/lm-sensors:

[...]
radeon-pci-0100
Adapter: PCI adapter
temp1:            +42.0°C  (crit = +120.0°C, hyst = +90.0°C)
[...]

To use the discrete graphics card globally, one can set the environment variable in /etc/environment:

DRI_PRIME=1

One might export it in the .bashrc as an alternative:

export DRI_PRIME=1

Or individually in front of the command, like above using glxgears:

Prime Synchronization

The x11-drivers/xf86-video-amdgpu driver does not support Prime Synchornization. This might cause tearing on monitors connected to the integrated GPU if the AMD GPU is set as the primary GPU. One possible workaround is to use the modesetting driver instead, to do this remove amdgpu from the VIDEO_CARDS variable. Or use a xorg configuration file to force the use of the modesetting driver. That being said, you might encounter other issues with the modesetting driver^[11].

Section "Device"
  Identifier "modesetting"
  Driver "modesetting"
EndSection

Another possible workaround is to set the integrated GPU as the primary GPU. This will not enable Prime Synchronization. However, tearing will be prevented nonetheless through AMD's TearFree. In this case it will be neccesairy to use the DRI_PRIME=1, VDPAU_DRIVER=radeonsi(for VDPAU) and LIBVA_DRIVER_NAME=radeonsi(for VAAPI) variables on applications that should be rendered on the AMD GPU.

VESA

If you have no other machine to browse web pages for solution - emerge x11-drivers/xf86-video-vesa This will allow you to use basic vesa driver so you can start X with no 3d and no 2d acceleration. Your usual kde/gnome/xfce or whatever else should start with vesa driver, so you can bootstrap yourself from within GUI.

Kernel

Processor type and features  --->
    [*] AMD Secure Memory Encryption (SME) support
    [ ]   Activate AMD Secure Memory Encryption (SME) by default

AMDGPU/RadeonSI drivers do not work

If the graphics card is not supported by including amdgpu and radeonsi alone in VIDEO_CARDS, try adding radeon to make.conf's VIDEO_CARDS definition. For example:

<syntaxhighlight lang="bash">VIDEO_CARDS="amdgpu radeonsi radeon"</syntaxhighlight>

After the values have been set update the system so the changes take effect:

Full-screen windows perform poorly

The installed version of sys-devel/llvm may be too old. Try emerging an unstable version.

Pixel-wide line on left side of screen when X server is started when using a Southern Island card

Those using a Southern Island card may notice a pixel-wide line on the left of the screen in both the X server and console environments after having started a X server (This issue doesn't exist when using Linux 4.13 or newer). This is a known bug. Disabling audio through HDMI for that display resolves this issue. This may be done via:

where HDMI-A-0 should be replaced by the name of the output, obtained by running xrandr

For more information please see https://bugs.freedesktop.org/show_bug.cgi?id=97861.