Document the possibility of setting default values for

mixer channels via boot loader.
While I am here, document the snd_driver metadriver.

1 files changed, 32 insertions, 2 deletions

diff --git a/en_US.ISO8859-1/books/handbook/multimedia/chapter.sgml b/en_US.ISO8859-1/books/handbook/multimedia/chapter.sgml
index bae4901e45..a505908dc1 100644
--- a/en_US.ISO8859-1/books/handbook/multimedia/chapter.sgml
+++ b/en_US.ISO8859-1/books/handbook/multimedia/chapter.sgml
@@ -192,7 +192,10 @@
     </indexterm>
 
     <para>To use your sound device, you will need to load the proper
-      device driver.  This may be accomplished in one of two ways.
+      device driver.  If you are not sure which driver to use, you may
+      try to load snd_driver, which is a metadriver loading the most common
+      device drivers at once, this speeds up the search for the correct driver.
+      Loading the device driver may be accomplished in one of two ways.
       The easiest way is to simply load a kernel module for your sound
       card with &man.kldload.8; which can either be done from the
       command line:</para>
@@ -522,7 +525,34 @@ pcm0: &lt;SB16 DSP 4.11&gt; on sbc0</screen>
       to 4 as in the above example.  On a system using &man.devfs.5;, the above will automatically be
       allocated transparently to the user.</para>
    </sect2>
-  </sect1>
+
+  <sect2>
+    <sect2info>
+      <authorgroup>
+	<author>
+	  <firstname>Josef</firstname>
+	  <surname>El-Rayes</surname>
+	  <contrib>Contributed by </contrib>
+	</author>
+      </authorgroup>
+    </sect2info>
+
+    <title>Setting default values for mixer channels</title>
+
+    <para>The default values for the different mixer channels are
+      hardcoded in the sourcecode of the pcm driver.  There are
+      a lot of different applications and daemons that allow
+      you to set values for the mixer they remember and set
+      each time they are started, but this is not a clean
+      solution, we want to have default values at the driver
+      level.  This is accomplished by defining the apropriate
+      values in <filename>/boot/loader.conf</filename>. E.g.:</para>
+<programlisting>pcm0.vol="100"</programlisting>
+
+    <para>This will set the vol channel to a default value of
+      100, as soon as the pcm module gets loaded.</para>
+  </sect2>
+</sect1>
 
   <sect1 id="sound-mp3">
     <sect1info>