I'm running with two displays HDMI-A-1 and eDP-1
I would expect this to reenable the just disabled head but this fails:
./wlr-randr --output HDMI-A-1 --off
./wlr-randr --output HDMI-A-1 --on
zwlr_output_configuration_head_v1@6: error 3: invalid custom mode
The last part of wayland-debug is:
[2732679.963] wl_callback@4.done(1702)
[2732679.984] -> zwlr_output_manager_v1@3.create_configuration(new id zwlr_output_configuration_v1@4, 981)
[2732679.999] -> zwlr_output_configuration_v1@4.enable_head(new id zwlr_output_configuration_head_v1@5, zwlr_output_head_v1@4278190111)
[2732680.013] -> zwlr_output_configuration_head_v1@5.set_mode(zwlr_output_mode_v1@4278190113)
[2732680.021] -> zwlr_output_configuration_head_v1@5.set_position(2560, 0)
[2732680.032] -> zwlr_output_configuration_head_v1@5.set_transform(0)
[2732680.039] -> zwlr_output_configuration_head_v1@5.set_scale(1.000000)
[2732680.047] -> zwlr_output_configuration_v1@4.enable_head(new id zwlr_output_configuration_head_v1@6, zwlr_output_head_v1@4278190080)
[2732680.060] -> zwlr_output_configuration_head_v1@6.set_custom_mode(0, 0, 0)
[2732680.074] -> zwlr_output_configuration_head_v1@6.set_position(0, 0)
[2732680.085] -> zwlr_output_configuration_head_v1@6.set_transform(0)
[2732680.092] -> zwlr_output_configuration_head_v1@6.set_scale(0.000000)
[2732680.100] -> zwlr_output_configuration_v1@4.apply()
[2732680.204] wl_display@1.error(zwlr_output_configuration_head_v1@6, 3, "invalid custom mode")
zwlr_output_configuration_head_v1@6: error 3: invalid custom mode
This works:
wlr-randr --output HDMI-A-1 --mode 2560x1440 --scale 1 --on
so it's a matter of picking good defaults when bringing up disabled heads.