Headphone audio on the Dell XPS 13 (2015) is quite noisy: there is loud white noise on both channels and an oscillating noise on the left channel.
Interestingly, running this Python script, which was written for the previous-gen XPS 13 (2013), greatly reduces the white noise and removes the oscillating noise: https://xps13-9333.appspot.com/root/usr/local/bin/white_noise_fix.py
Two kernel patches were committed for 3.16 that fixed the issue permanently for the 2013 XPS 13:
It may be necessary to apply similar quirks for the ALC286 chipset in the 2015 XPS 13.
I've tested this issue on kernels 4.0.1 through 4.1-rc6.
Could you give alsa-info.sh output?
Created attachment 179971 [details]
Could you try the latest sound git tree for-linus branch with the patch below?
Created attachment 179981 [details]
Test fix patch
Yes, that patch fixes it. Thanks for the quick response!
Thanks for a quick test. I queued the fix now to git tree. It'll be included in 4.1 final.
Side effect of this fix : the internal microphone doesn't work anymore and doesn't appear in alsamixer (no issue with 4.1-rc8).
Any idea why ?
Please give alsa-info.sh output to compare.
Created attachment 180751 [details]
alsa-info - 4.1-rc8 - microphone working
Created attachment 180761 [details]
alsa-info - 4.1 - microphone not working
Can confirm that the fix caused a regression in headset/mic support. My apologies for not catching it in my testing earlier.
The fix for the mic was already included in for-linus branch. Will be upstreamed in this week.
I just tested it and the fix works great. Thanks for the update!
Created attachment 184291 [details]
Microphone stops working after plugging in the headset
Unfortunately the issue with microphone still persists:
I'm using Fedora 22, kernel 4.1.3-200.fc22.x86_64 on my laptop Lenovo M30-70.
On the system's start the internal microphone works well, however if I try to plug in the headset with its own microphone it doesn't work at all as well as internal microphone even after I plug off the headset. Only the white noise can be heard.
I tested it with several headsets with the same result.
P.S. with the kernel 4.0.8 everything works just fine.
Your machine is totally different. Please open another bug to track.
In the new opened bug, attach alsa-info.sh outputs at working (4.0.x kernel) and non-working cases. At best, give both the headset plugged and unplugged states.
Thanks for your advise.
I opened it here https://bugzilla.kernel.org/show_bug.cgi?id=102521