FixSound

The FixSound activity provides a workaround for some bugs that were shipped in OLPC OS releases. In such cases, sound in OpenFirmware works fine, but a software bug prevents sound from working in Linux and the user interface.

These problems can be fixed easily at the Terminal. However, running syntax-sensitive commands in the Terminal is not always appropriate (e.g. for children or non-technical support staff). So I have produced an activity to do this for you.

Then you will see the "Fix sound" activity added to the home screen. It has a Speaker icon. Simply run this activity every time you experience a loss of sound - it will apply the workaround, and then exit after 5 seconds.

v2

<trac>12683</trac> describes a bug where XO-1.75 audio is commonly lost in the field. In this case, audio output through the speakers is silent, but audio can be heard through headphones if they are later connected.

The following command solves the problem:

amixer sset Speaker 0dB unmute

Here is an activity that executes the command on your behalf: http://dev.laptop.org/~dsd/FixSound/FixSound-2.xo

v1

<trac>9248</trac> describes a bug commonly seen in all OLPC deployments: after some time, sound support will be lost in all Sugar activities. Their output is simply silent. No error messages are logged. When this happens, sound from Open Firmware is still perfectly functional: you can still hear the bootup sound (presuming that the user did not mute it by pressing the volume-down key during boot), and sound playback works fine during the Open Firmware rocker-left self tests.

This is due to a bug in the OLPC operating system. As of OLPC OS v8.2.1, this bug is still unfixed, but the problem does seem to disappear from later releases (as we haven't heard further reports from the community). It is not exactly known which activities or components cause this loss of sound to happen. Suspects are Speak, Measure, and Adobe Flash.

The following command solves the problem:

amixer sset PCM 90% unmute

Here is an activity that executes the command on your behalf: http://dev.laptop.org/~dsd/FixSound/FixSound-1.xo