I don't know. I filled a first bug for lightdm since it was unable to honor the rotation information.
I was answered that it was related to gnome-settings-daemon that was not supported by the greeter.
Now the greeter works ok (the screen is in the correct orientation) but the greeter seems to think that the length and the height are the one of the screen instead of the new rotated (length and heigth are swapped).
I don't know. I filled a first bug for lightdm since it was unable to honor the rotation information. daemon that was not supported by the greeter.
I was answered that it was related to gnome-settings-
Now the greeter works ok (the screen is in the correct orientation) but the greeter seems to think that the length and the height are the one of the screen instead of the new rotated (length and heigth are swapped).
I don't know if I'm clear enough.