TL;DR: My Thinkpad X240 seems to be affected by the problem described in bug #1101386. The patch [1] adds quirk for T440s, perhaps adding similar line for X240 would fix this? [1] http://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/?id=1c37c22332a2d2c1b4ab32177a4f847c7fe06e38 Description of problem: If my Thinkpad X240 is connected to the docking station and the audio cable is plugged in the dock there is no audio output on the speakers. If I connect the audio cable directly to the Thinkpad I can hear the audio output. Version-Release number of selected component (if applicable): kernel-3.16.3-200.fc20.x86_64 alsa-lib-1.0.27.2-2.fc20.x86_64 How reproducible: Always. Steps to Reproduce: 1. Put the X240 into dock. Connect headphones to the docking station jack. 2. Unmute and set everything to 100 % in alsamixer. 3. Play some audio. Actual results: No audio output from the dock. Expected results: Music:) Additional info: http://www.alsa-project.org/db/?f=c7c6834a5d537680f44aed2c61e54ab8711b1391
Works on F21 now after upgrading to a 3.18 line kernel
*********** MASS BUG UPDATE ************** We apologize for the inconvenience. There is a large number of bugs to go through and several of them have gone stale. Due to this, we are doing a mass bug update across all of the Fedora 20 kernel bugs. Fedora 20 has now been rebased to 3.18.7-100.fc20. Please test this kernel update (or newer) and let us know if you issue has been resolved or if it is still present with the newer kernel. If you have moved on to Fedora 21, and are still experiencing this issue, please change the version to Fedora 21. If you experience different issues, please open a new bug report for those.
Works on F20 as well. Thanks whoever fixed this!