AMD Navi GPU troubleshooting

Due to long standing persistent issues that affect AMD Navi GPUs on Linux, it's worth to systematically organize bug reports, to help developers narrow down those issues.

• If you can, please capture dmesg of the hang and link to it in your report.

GPU hangs

Random desktop freezes with ERROR ring gfx_0.0.0 timeout

Note: If known, please add info on the application that's causing the freeze.

GPU model	Kernel	Mesa version	llvm version	aco	Desktop environment and session	Distro	Firmware version	Other details (motherboard, PCIe mode, etc.).	Application that causes the freeze	status
Sapphire Pulse RX 5700 XT	5.6-rc5	20.0.0	9.0.1	—	KDE Plasma 5.17.5 (X11)	Debian testing	19.05	Asrock X570 Taichi, PCIe4		stable
MSI Radeon RX 5700 XT GAMING X	5.5.9-arch1-2	19.3.4-2	9.0.1-2	—	KDE Plasma 5.18.3-1 (X11)	Arch	19.1.0-1	MSI B450 TOMAHAWK MAX, PCIe3		stable
Gigabyte Aorus RX 5700 XT	5.5.7	20.0.1	9.0.1	—	XFCE 4.12.2 (X11)	Ubuntu 18.04	?	Gigabyte X570 Aorus Elite, PCIe4, dmesg	steamwebhelper?	hangs rarely
Saphire Pulse RX 5700	5.6.0-rc4-1-amd-drm-fixes	20.1.0	11.0.0	—	KDE Plasma 5.18.3	Arch		Asus Prime x370 Pro, PCIe3	Björk Vulnicura Virtual Reality Album	hangs
MSI RX 5500 XT 8GB	linux-amd-drm-fixes-5.6	19.3.5, 20.1.0	9.0.1	—	KDE Plasma	Manjaro	OE	BIOSTAR X370GT5, PCIe3	plasmashell, PID 0	hangs
SAPPHIRE PULSE RX 5600 XT 6GB	linux-amd-drm-next-5.6	19.3.5, 20.1.0, 20.0.0, mesa-aco-20.0.0_devel	9.0.1, 11.0.0-rc	yes	Plasma, Deepin, GNOME, Budgie	Manjaro/Arch/ArcoLinux/Pop_OS!	-	ASRock B450M/AC, PCIe3	plasmashell,gnomeshell, DDE, Titanfall2, Resident Evil 7	hangs
Gigabyte RX 5700 XT Gaming OC	5.5.0	20.0.2	9.0.1	yes	GNOME Shell 3.34.3 (Wayland)	Ubuntu 19.10	20190923	Gigabyte X570 Aorus Master, PCIe4	Firefox (Google Maps), must set AMD_DEBUG=nongg	stable }