EACCES can mean someone else has opened the device too. eg similar to the plymouth/lightdm/xorg-server race.
This can be plymouth or xorg-server. Plymouth should be completely dead before starting mir, or become a mir client so it doesn't need to open the device node. Xorg-server needs to be started AFTER mir has opened the drm_fd.
EACCES can mean someone else has opened the device too. eg similar to the plymouth/ lightdm/ xorg-server race.
This can be plymouth or xorg-server. Plymouth should be completely dead before starting mir, or become a mir client so it doesn't need to open the device node. Xorg-server needs to be started AFTER mir has opened the drm_fd.