[Latitude E7440, Realtek ALC292, Green Headphone Out, Front] No automute on speakers when headphones plugged

[Léa LE BARON]

I have a Dell computer, Latitude E7440 model (apparently with Realtek ALC292 soundcard)
Bought it with Ubuntu pre-installed on it, but wiped out Ubuntu to install Windows 8
Then, a few months later, I put a double-boot with Windows 8 and Ubuntu 14.04.4 LTS
At first, everything worked just fine for a while

And then, I think the problem appeared when my computer, on Windows 8, ran out of battery and shut down by itself, then I started it again, but it went on Ubuntu instead of Windows (whereas Windows needed to install some updates)

From then, 2 problems appeared :
1. On Windows, the sound doesn't come out of the jack plug anymore. I need to shut down and up my computer several times for the sound to come out the jack, and when it finally comes out fine, it still comes out the front speakers but I can mute it (when I hit the mute button, the speakers go mute, but not the jack, I really don't know why)

2. On Ubuntu, the sound comes out from both jack and speakers at the same time, there is no auto-mute when I plug something
I tried to resolve the problem by changing some configuration in alsa-base.conf and in alsamixer, but it appears nothing I change in alsamixer has any influence on the sound at the end (also the "Enabled" option on the "Auto-mute" field is not available on my computuer, I have no idea why...)

I thank you in advance for the help you can give me
(Sorry if my explication is not quite clear, I'm French)

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: alsa-base 1.0.25+dfsg-0ubuntu4
ProcVersionSignature: Ubuntu 3.13.0-46.79-generic 3.13.11-ckt15
Uname: Linux 3.13.0-46-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.21
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: lea 1924 F.... pulseaudio
 /dev/snd/controlC1: lea 1924 F.... pulseaudio
CurrentDesktop: Unity
Date: Wed Oct 11 12:15:24 2017
InstallationDate: Installed on 2014-07-14 (1184 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
PackageArchitecture: all
SourcePackage: alsa-driver
Symptom: audio
Symptom_Card: Audio interne - HDA Intel PCH
Symptom_Jack: Green Headphone Out, Front
Symptom_Type: No auto-mute between outputs
Title: [Latitude E7440, Realtek ALC292, Green Headphone Out, Front] No automute
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 05/08/2017
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A21
dmi.board.name: 0T21G7
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 9
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA21:bd05/08/2017:svnDellInc.:pnLatitudeE7440:pvr00:rvnDellInc.:rn0T21G7:rvrA00:cvnDellInc.:ct9:cvr:
dmi.product.name: Latitude E7440
dmi.product.version: 00
dmi.sys.vendor: Dell Inc.
mtime.conffile..etc.modprobe.d.alsa.base.conf: 2017-10-10T18:18:47.904575