Saturday, November 27, 2010
Fixing a Linux regression defect
This bug is an excellent example of the continual (aka "seemingly endless") process of verifying that hardware works correctly with Ubuntu (and more broadly, current versions of Linux). Briefly, in mid-May 2007, a patch was committed to upstream ALSA adding support for a particular machine. At the time that the patch was merged, support for certain BIOSes was quite suboptimal. Fast forward to late-November 2010, and a user's "sound no longer works," i.e., playback is inaudible through both speakers and headphones jack when using Ubuntu Maverick. In the realm of kernel code, particularly drivers, certain high-profile subsystems move relatively quickly, and given the vast amount of PC hardware, it's nearly impossible to verify that every released version of Ubuntu (much less upstream Linux) doesn't regress some hardware support. It's a difficult and thankless job, but someone has to do it.