LTSP | LTSP5 Client Sound | Unmute Fix


There is a problem with some sound cards that start up muted. This installs a script which responds to settings in lts.conf.

To test this, whilst logged onto the client type:

# alsamixer

If the main volume is at nil and there is “MM” (Muted left and Muted right) at the bottom of the slider, then pressing M to unmute, and the cursor keys to increase the volume, will resolve the problem. You can experiment with the different channels, like PCM, FRONT and MASTER. Play to your heart’s content, any changes will be lost on reboot.

The only thing is that this fix will be lost next time you boot the client.

Step 1: Install Script

# Copyright Gideon Romm, Symbio Technologies
# Released under GPLv2
# This is a script to set up certain things 
# that are not already setup in an SBA environment
# Specifically:
#   1. restore sound levels
# lts.conf:

echo "Restoring sound levels" > /tmp/unmute.log

while [ $? != 0 ]; do
sleep 1

# Set up local environment
if [ -f /etc/lts.conf ]; then
    eval `getltscfg -a`

# Set up sound
if [ -n "$VOLUME" ]; then
amixer sset Master,0 ${VOLUME}% unmute 2>/dev/null
echo "amixer sset Master,0 ${VOLUME}% unmute 2: $?" >> /tmp/unmute.log
amixer sset 'Master Digital',0 ${VOLUME}% unmute 2>/dev/null
echo "amixer sset 'Master Digital',0 ${VOLUME}% unmute 2: $?" >> /tmp/unmute.log
amixer sset Headphone,0 ${HEADPHONE_VOLUME:-$VOLUME}% unmute 2>/dev/null
echo "amixer sset Headphone,0 ${HEADPHONE_VOLUME}% unmute 2: $?" >> /tmp/unmute.log

if [ -n "$PCM_VOLUME" ]; then
amixer sset PCM,0 ${PCM_VOLUME}% unmute 2>/dev/null
echo "amixer sset PCM,0 ${PCM_VOLUME}% unmute 2: $?" >> /tmp/unmute.log

if [ -n "$MIC_VOLUME" ]; then
amixer sset Mic,0 ${MIC_VOLUME}% unmute cap 2>/dev/null
echo "amixer sset Mic,0 ${MIC_VOLUME}% unmute 2: $?" >> /tmp/unmute.log

if [ -n "$CD_VOLUME" ]; then
amixer sset CD,0 ${CD_VOLUME}% unmute 2>/dev/null
echo "amixer sset CD,0 ${CD_VOLUME}% unmute 2: $?" >> /tmp/unmute.log

if [ -n "$FRONT_VOLUME" ]; then
amixer sset Front,0 ${FRONT_VOLUME}% unmute 2>/dev/null
echo "amixer sset Front,0 ${FRONT_VOLUME}% unmute 2: $?" >> /tmp/unmute.log

echo "Sound levels restored" >> /tmp/unmute.log

Step 2: Generate rc.d

$ sudo chroot /opt/ltsp/i386
# update-rc.d unmute defaults
# exit
$ sudo ltsp-update-image

Step 3: Configure lts.conf

Use the following settings for the particular client:

VOLUME            = 100
PCM_VOLUME        = 100
MIC_VOLUME        = 100
CD_VOLUME         = 100
FRONT_VOLUME      = 100

Step 4: Reboot client

Reboot the client. You can check that the script has run by looking at /tmp/unmute.log on the client. You can get to the client by pressing Ctrl-Alt-F1 and logging in with the root password.


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