$ lspci -nn | grep -i audio 00:03.0 Audio device [0403]: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor HD Audio Controller [8086:0c0c] (rev 06) 00:1b.0 Audio device [0403]: Intel Corporation 8 Series/C220 Series Chipset High Definition Audio Controller [8086:8c20] (rev 05) When plugging the headphones audio still comes out of speakers. The headphones output seems to be totally missing as the external microphone input line. I tried with pasuspender -- speaker-test -c2 -twav -Dhw:PCH to get pulseaudio out of the equation and I can reproduce. I'm going to attach the output fo alsa-info.sh for the system with and without headphones plugged in shortly.
Created attachment 183721 [details] alsa-info no headphones, working speakers This is the output of alsa-info.sh when no headphones are plugged in, sounds comes out of speakers as expected.
Created attachment 183731 [details] alsa-info headphones plugged in This is the output of alsa-info.sh when headphones are plugged in the 3.5 mm stereo jack. Sound still coming out of speakers. Note the "HP/Speaker Auto Detect" switch is enabled in alsamixer (having it disabled seems to have no effect). The "HP/Speaker" one have no effect as well. Kernel is 4.1.2 but issue was present in 4.0 series from .4 to .8 as well. OS is Fedora 22
Good news: Fedora updated to kernel 4.2.5 and jack detection for headphones works out of the box. I guess it was backported from kernel 4.3. For reference see also bug #101981 comments up to 19 (we possibly mixed up the discussion for the two bugs :P ). I didn't checked yet if anything changed for the microphone jack, but looking at the git logs situation should be unchanged compared to the last update on bug bug #101981 (at the time of this writing, comment 20)
Yeah, we got a patch to correct the output pin assignment specific to Alienware 15 recently. If the input doesn't work as expected, check the code in patch_ca0132.c ca0132_config() function, and fiddle with the pin assignment there. Let me know the result.