tbsm may run desktop sessions, such as dwm, without dbus support.
Thus, here are 2 methods for autostarting dbus upon login:

1. Please add the following line to .xinitrc or .xsession:
exec dbus-launch --sh-syntax --exit-with-session dwm

2. Please add the following lines to autostart.sh (dwm has an optional
patch for autostarting ~/.dwm/autostart.sh):

# Start DBUS session bus:
if [ -z "$DBUS_SESSION_BUS_ADDRESS" ]; then
   eval $(dbus-launch --sh-syntax --exit-with-session)
fi