Riddling over systemctl, pulseaudio, firefox-esr, and salsa.debian.org

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

i experience a strange behavior of my Debian 11 with firefox-esr and
pulseaudio.
After visiting
  https://salsa.debian.org/groups/optical-media-team/-/activity
the most busy process on my Debian 11 is the one that was started at boot
(or user login) automatically by
  /usr/bin/pulseaudio --daemonize=no --log-target=journal
It uses tenfold more CPU time than the idle firefox-esr (says top(1)).
I cannot tell whether it really tries to make noise, because no
loudspeakers are attached.
Before the visit to salsa.debian.org pulseaudio is not shown by top(1)
among the busiest processes. Afterwards it steadily uses 10 percent of
a 4 GHz Xeon core.
Leaving the web site and even removing the browser tab does not reduce
this activity.

So what is salsa.debian.org doing with firefox-esr to get pulseaudio so
excited ?


Next riddle is how i could keep pulseaudio from being started automatically
for my desktop user. I understand from web and man page of systemctl that
  systemctl --user disable pulseaudio.service pulseaudio.socket
should do the trick.
But on next boot and login (even via ssh) there is again a pulseaudio
instance running with my desktop user id.
The superuser can prevent the starting of pulseaudio for my user and for
user "lightdm" by
  systemctl --global disable pulseaudio.service pulseaudio.socket

So do i get the man page wrong and systemctl has no means to prevent
services for particular users ?


Have a nice day :)

Thomas