Je confirme l'efficacité des modifs, plus de 2 mois sans aucun soucis, ça fait plaisir de ne plus killer pulseaudio toutes les 5 min. 
Et dire que je me traînait ce bug depuis l'achat de la config en octobre 2013 ! 
Pour rappel (j’adore inxi, vraiment très pratique)
renaud@renaud-pc:~$ inxi -F
System:    Host: renaud-pc Kernel: 4.15.0-45-generic x86_64 bits: 64 Desktop: MATE 1.20.1
           Distro: Ubuntu 18.04.2 LTS
Machine:   Device: desktop Mobo: ASUSTeK model: M5A97 R2.0 v: Rev 1.xx serial: N/A
           BIOS: American Megatrends v: 2603 date: 06/26/2015
CPU:       8 core AMD FX-8350 Eight-Core (-MCP-) cache: 16384 KB
           clock speeds: max: 4000 MHz 1: 1855 MHz 2: 1772 MHz 3: 2350 MHz 4: 1486 MHz 5: 1795 MHz 6: 1959 MHz
           7: 1401 MHz 8: 1403 MHz
Graphics:  Card: Advanced Micro Devices [AMD/ATI] Ellesmere [Radeon RX 470/480/570/570X/580/580X]
           Display Server: x11 (X.Org 1.19.6 ) drivers: amdgpu (unloaded: modesetting)
           Resolution: 1600x900@59.98hz, 1680x1050@59.95hz
           OpenGL: renderer: Radeon RX 570 Series (POLARIS10, DRM 3.23.0, 4.15.0-45-generic, LLVM 7.0.0)
           version: 4.5 Mesa 18.2.2
Audio:     Card-1 Advanced Micro Devices [AMD/ATI] Ellesmere [Radeon RX 580] driver: snd_hda_intel
           Card-2 Advanced Micro Devices [AMD/ATI] SBx00 Azalia (Intel HDA) driver: snd_hda_intel
           Sound: Advanced Linux Sound Architecture v: k4.15.0-45-generic
Network:   Card: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller driver: r8169
           IF: enp2s0 state: up speed: 1000 Mbps duplex: full mac: d8:50:xx:xx:xx:xx
Drives:    HDD Total Size: 2000.4GB (60.0% used)
           ID-1: /dev/sda model: WDC_WD5002AALX size: 500.1GB
           ID-2: /dev/sdb model: WDC_WD10EARS size: 1000.2GB
           ID-3: /dev/sdc model: ST500DM002 size: 500.1GB
Partition: ID-1: / size: 37G used: 22G (62%) fs: ext4 dev: /dev/sda8
           ID-2: swap-1 size: 1.00GB used: 0.00GB (0%) fs: swap dev: /dev/sda6
RAID:      No RAID devices: /proc/mdstat, md_mod kernel module present
Sensors:   System Temperatures: cpu: 16.2C mobo: N/A gpu: 31.0
           Fan Speeds (in rpm): cpu: 0
Info:      Processes: 262 Uptime: 13:20 Memory: 3784.5/9890.0MB Client: Shell (bash) inxi: 2.3.56