Si tu utilises radeon les paramètres sont là
https://www.x.org/archive/X11R6.8.0/doc/radeon.4.html
et
modinfo radeon
dit
filename: /lib/modules/5.3.0-3-amd64/kernel/drivers/gpu/drm/radeon/radeon.ko
parm: no_wb:Disable AGP writeback for scratch registers (int)
parm: modeset:Disable/Enable modesetting (int)
parm: dynclks:Disable/Enable dynamic clocks (int)
parm: r4xx_atom:Enable ATOMBIOS modesetting for R4xx (int)
parm: vramlimit:Restrict VRAM for testing, in megabytes (int)
parm: agpmode:AGP Mode (-1 == PCI) (int)
parm: gartsize:Size of PCIE/IGP gart to setup in megabytes (32, 64, etc., -1 = auto) (int)
parm: benchmark:Run benchmark (int)
parm: test:Run tests (int)
parm: connector_table:Force connector table (int)
parm: tv:TV enable (0 = disable) (int)
parm: audio:Audio enable (-1 = auto, 0 = disable, 1 = enable) (int)
parm: disp_priority:Display Priority (0 = auto, 1 = normal, 2 = high) (int)
parm: hw_i2c:hw i2c engine enable (0 = disable) (int)
parm: pcie_gen2:PCIE Gen2 mode (-1 = auto, 0 = disable, 1 = enable) (int)
parm: msi:MSI support (1 = enable, 0 = disable, -1 = auto) (int)
parm: lockup_timeout:GPU lockup timeout in ms (default 10000 = 10 seconds, 0 = disable) (int)
parm: fastfb:Direct FB access for IGP chips (0 = disable, 1 = enable) (int)
parm: dpm:DPM support (1 = enable, 0 = disable, -1 = auto) (int)
parm: aspm:ASPM support (1 = enable, 0 = disable, -1 = auto) (int)
parm: runpm:PX runtime pm (1 = force enable, 0 = disable, -1 = PX only default) (int)
parm: hard_reset:PCI config reset (1 = force enable, 0 = disable (default)) (int)
parm: vm_size:VM address space size in gigabytes (default 4GB) (int)
parm: vm_block_size:VM page table size in bits (default depending on vm_size) (int)
parm: deep_color:Deep Color support (1 = enable, 0 = disable (default)) (int)
parm: use_pflipirq:Pflip irqs for pageflip completion (0 = disable, 1 = as fallback, 2 = exclusive (default)) (int)
parm: bapm:BAPM support (1 = enable, 0 = disable, -1 = auto) (int)
parm: backlight:backlight support (1 = enable, 0 = disable, -1 = auto) (int)
parm: auxch:Use native auxch experimental support (1 = enable, 0 = disable, -1 = auto) (int)
parm: mst:DisplayPort MST experimental support (1 = enable, 0 = disable) (int)
parm: uvd:uvd enable/disable uvd support (1 = enable, 0 = disable) (int)
parm: vce:vce enable/disable vce support (1 = enable, 0 = disable) (int)
parm: si_support:SI support (1 = enabled (default), 0 = disabled) (int)
parm: cik_support:CIK support (1 = enabled (default), 0 = disabled) (int)
un bon wiki https://wiki.archlinux.org/index.php/ATI
C’est pourquoi j’ai mis radeon.pcie_gen2=0 dans grub