From 88c59ff9c625460a094422622aec827491f12388 Mon Sep 17 00:00:00 2001
From: Pauli Virtanen <pav@iki.fi>
Date: Wed, 6 Dec 2023 21:05:00 +0200
Subject: [PATCH] docs: explain runtime logging controls

---
 docs/rst/daemon/logging.rst | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/docs/rst/daemon/logging.rst b/docs/rst/daemon/logging.rst
index 39bac1fe..6717c2f1 100644
--- a/docs/rst/daemon/logging.rst
+++ b/docs/rst/daemon/logging.rst
@@ -100,6 +100,33 @@ If a ``<topic pattern>`` is not specified, then the given ``<level>`` is
 considered to be the global log level, which applies to all topics that have
 no explicit level specified.
 
+Changing log level at runtime
+-----------------------------
+
+The debug log level can be changed at runtime using ``wpctl``:
+
+.. code::
+
+   wpctl set-log-level D     # enable debug logging for Wireplumber
+   wpctl set-log-level -     # restore default logging for Wireplumber
+
+   wpctl set-log-level 0 4   # enable debug logging for Pipewire daemon
+   wpctl set-log-level 0 -   # restore default logging for Pipewire daemon
+
+Equivalently, it is also possible to adjust the logging by setting
+``log.level`` in the ``settings`` metadata:
+
+.. code::
+
+   pw-metadata -n settings <ID> log.level "D"   # WirePlumber logging
+
+   pw-metadata -n settings 0 log.level 4        # PipeWire daemon logging
+
+Above, ``<ID>`` should be replaced by the WirePlumber daemon client ID.
+
+Note that PipeWire daemon log levels must be specified by numbers, not
+letter codes.
+
 Examples
 --------