Archive for May, 2012

David Henningsson

Three audio bugs that need your hardware info

Are you:

  • Missing speakers or internal mic in sound settings?
  • Seeing a S/PDIF device show up for your USB device?
  • Having no or extremely low sound from your internal microphone?

If so, I might need your help to be able to fix it for you!

In Ubuntu 12.04 – and very likely, other recent distribution releases as well – there are at least these three audio bugs that need manual quirking for every machine. This means that you submit your hardware info in the meta-bug, I will look in that info for some ID numbers and include them in a list of devices for which a specific workaround has to be applied. We can’t apply the workaround for every device, as that could potentially cause problems for other devices.

So if you’re suffering from one of the bugs I’m describing below, I could use your help to make sure they are fixed for future releases of Ubuntu and ALSA/PulseAudio.

Missing speakers or internal mic in sound settings

If you’re suffering from one of the following problems:

1) In the sound settings dialog, when you plug your headphones into the designated 3.5 mm jack, there is a “Headphones” device correctly shown, but when you unplug it, there is no “Speaker” device shown, even though you have internal speakers on your computer.

2) In the sound settings dialog, when you plug your external microphone into the designated 3.5 mm jack, there is a “Microphone” (or similar) device correctly shown, but when you unplug it, there is no “Internal Mic” device shown, even though you have an internal mic on your computer.

Then you might be suffering from bug 946232. Please look in that bug for your device in that list, and if it is not there, try the workaround and if it’s working, add your alsa-info as suggested in the bug. Thanks!

S/PDIF device showing up for your USB device

If you have a USB headset, or another USB device that does not have any S/PDIF output, but yet sometimes there is an extra device called “Digital Output (S/PDIF)” for that device in Sound Preferences. If so, you’re likely suffering from bug 1002952. At the time of this writing there are also a few devices that are on their way to becoming fixed, if you have one of these, please help out with testing the proposed repository. There is more information in bug 1002952 about that.

Inverted Internal Mic

In this case, you have an internal mic showing up, but it seems not to work: it’s either completely silent, or you can possibly pick a very small sound, with much background noise, even though you have set gain to maximum.

There is something you could try. Install the pavucontrol application, start it and go to the “Input Devices” tab. Unlock the channels (click the keylock icon), then mute the right channel while keeping the left channel at the volume you want.
If the internal mic is now working correctly, you have an inverted internal mic, so that your right channel cancels out the left one. (Why the hardware is constructed that way is beyond me.)
This seems to be most common on Acer Aspire laptops, but I’ve seen them on other laptops as well, and fixing these are more of a long term project as they are non-trivial kernel patches. So far I’ve created a patch for Thinkpad U300s. Anyway, I would like to track the remaining ones in bug 1002978, so please add your system there according to the instructions.

Last but not least – thanks in advance for helping Ubuntu, as well as the greater Linux ecosystem (I’ll make sure that the patches pushed into Ubuntu gets upstream as well)!