Am 26.08.21 um 18:45 schrieb Alex
Deucher:
On Thu, Aug 26, 2021 at 12:35 PM Paul <pb.g@xxxxxx> wrote:Hi there Out of curiosity I would like to ask if it is possible to set a kernel command line parameter for my Radeon 6900XT that sets a specific resolution and refresh rate of a specific connected monitor. Ideally this parameter is set to the monitors used desktop (X11, Wayland) resolution/refreshrate. I did this for years with my Intel IGP's. I appended: video=HDMI-A-1:1920x1080@50 to the kernel command line. This worked beautifully and the result was my monitor was preconfigured to a specific resolution and refresh rate from the first lines of the kernel to the desktop (X11) and it did not had to switch to anything else in between. Another nice side effect is when in X11 one switches to the console, or vice versa, via STRG+Fx, pretty much everyone has this annoying delay because the monitor has to switch between refresh rates again. With that preconfigured settings at boot this gave a very satisfying feeling, especially if one frequently switches between console and X11 (or wayland maybe). Is this kind of parameter implemented in the kernel/amdgpu driver?It works the same for all drivers. Just make sure the connector name is correct. Alex
Thank you, it works.
I just want to mention that I had to look in "/sys/class/drm/" for the correct connector naming. Connector names shown by xrandr are different:
ls /sys/class/drm/ | grep card0-
card0-DP-1 # DP-1
card0-DP-2 # DP-2
card0-DP-3 # DP-3
card0-HDMI-A-1 # HDMI-A-1
vs.
xrandr | grep connected | awk '{print $1}'
DisplayPort-0
DisplayPort-1
DisplayPort-2
HDMI-A-0
