the solution proposed in https://bugzilla.redhat.com/show_bug.cgi?id=1534300 and https://bugs.freedesktop.org/show_bug.cgi?id=93782 solved the problem. one should add
video=SVIDEO-1:d to the kernel parameters, best in /etc/defaults/grub ** Bug watch added: Red Hat Bugzilla #1534300 https://bugzilla.redhat.com/show_bug.cgi?id=1534300 ** Bug watch added: freedesktop.org Bugzilla #93782 https://bugs.freedesktop.org/show_bug.cgi?id=93782 -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to libdrm in Ubuntu. https://bugs.launchpad.net/bugs/1789258 Title: drm:drm_atomic_helper_wait_for_dependencies flip_done timed out To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/libdrm/+bug/1789258/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp