AMDGPU: without cable attached videocard shuts down and does not wake up again, log prints "[drm] Cannot find any crtc or sizes"

[ed20900]

Linux boot shows the message in the title of this bug report if the videocard does not have any output attached. The computer boots up and when Linux starts loading, the card shuts down: fans stop spinning and the LED of the logo turns off. It's a Sapphire Radeon RX 580. If I attach the cable past this point the card does not turn on again. Pressing keys on the keyboard, moving the mouse or turning off and on the monitor does not awake the GPU.

> amdgpu 0000:27:00.0: amdgpu: SE 4, SH per SE 1, CU per SH 9, active_cu_number
> 36
> amdgpu 0000:27:00.0: [drm] Cannot find any crtc or sizes
> [drm] Initialized amdgpu 3.40.0 20150101 for 0000:27:00.0 on minor 0

If there's an output device attached to the videocard, then it prints this text:
> amdgpu 0000:27:00.0: amdgpu: SE 4, SH per SE 1, CU per SH 9, active_cu_number
> 36
> [drm] fb mappable at 0xE0BEB000
> [drm] vram apper at 0xE0000000
> [drm] size 7299072
> [drm] fb depth is 24
> [drm] pitch is 6912
> fbcon: amdgpudrmfb (fb0) is primary device
> EDAC amd64: F17h detected (node 0).
> EDAC amd64: Node 0: DRAM ECC disabled.
> Console: switching to colour frame buffer device 210x65
> amdgpu 0000:27:00.0: [drm] fb0: amdgpudrmfb frame buffer device
> [drm] Initialized amdgpu 3.40.0 20150101 for 0000:27:00.0 on minor 0

In order to workaround this issue I have to pass Linux the parameter amdgpu.runpm=0.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: xserver-xorg-video-amdgpu 19.1.0-1 [modified: usr/share/X11/xorg.conf.d/10-amdgpu.conf]
Uname: Linux 5.10.10-051010-generic x86_64
.tmp.unity_support_test.0:

ApportVersion: 2.20.11-0ubuntu27.16
Architecture: amd64
BootLog:

CasperMD5CheckResult: skip
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: None
CurrentDesktop: ubuntu:GNOME
CurrentDmesg: Error: command ['dmesg'] failed with exit code 1: dmesg: read kernel buffer failed: Operation not permitted
Date: Mon Mar 8 16:53:25 2021
DistroCodename: focal
DistroVariant: ubuntu
GraphicsCard:
 Advanced Micro Devices, Inc. [AMD/ATI] Ellesmere [Radeon RX 470/480/570/570X/580/580X/590] [1002:67df] (rev e7) (prog-if 00 [VGA controller])
   Subsystem: Sapphire Technology Limited Nitro+ Radeon RX 570/580/590 [1da2:e366]
InstallationDate: Installed on 2014-06-05 (2467 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
MachineType: Micro-Star International Co., Ltd. MS-7B79
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-5.10.10-051010-generic root=UUID=c46a90a3-0e37-4fb0-87ea-a14d4713dfc4 ro iommu=pt ignore_loglevel log_buf_len=134217728 amdgpu.runpm=0 crashkernel=512M-:192M
SourcePackage: xserver-xorg-video-amdgpu
UpgradeStatus: Upgraded to focal on 2020-04-26 (315 days ago)
dmi.bios.date: 06/11/2020
dmi.bios.release: 5.14
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: H.60
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: X470 GAMING PLUS MAX (MS-7B79)
dmi.board.vendor: Micro-Star International Co., Ltd.
dmi.board.version: 3.0
dmi.chassis.asset.tag: To be filled by O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: Micro-Star International Co., Ltd.
dmi.chassis.version: 3.0
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrH.60:bd06/11/2020:br5.14:svnMicro-StarInternationalCo.,Ltd.:pnMS-7B79:pvr3.0:rvnMicro-StarInternationalCo.,Ltd.:rnX470GAMINGPLUSMAX(MS-7B79):rvr3.0:cvnMicro-StarInternationalCo.,Ltd.:ct3:cvr3.0:
dmi.product.family: To be filled by O.E.M.
dmi.product.name: MS-7B79
dmi.product.sku: To be filled by O.E.M.
dmi.product.version: 3.0
dmi.sys.vendor: Micro-Star International Co., Ltd.
version.compiz: compiz 1:0.9.14.1+20.04.20200211-0ubuntu1
version.libdrm2: libdrm2 2.4.102-1ubuntu1~20.04.1
version.libgl1-mesa-dri: libgl1-mesa-dri 20.2.6-0ubuntu0.20.04.1
version.libgl1-mesa-glx: libgl1-mesa-glx 20.2.6-0ubuntu0.20.04.1
version.xserver-xorg-core: xserver-xorg-core 2:1.20.9-2ubuntu1.2~20.04.1
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.10.6-1
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20200226-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.16-1
xserver.bootTime: Mon Feb 4 17:21:56 2019
xserver.configfile: default
xserver.errors:
 [drm] Failed to open DRM device for pci:0000:01:00.0: -19
 open /dev/dri/card0: No such file or directory
 open /dev/dri/card0: No such file or directory
 Screen 0 deleted because of no matching config section.
xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:

xserver.version: 2:1.20.1-3ubuntu2.1