after upgrading to 4.12 kernel there is no sound anymore.

OCcasionaly the amplifier triggers (hearing a bop in the speakers), but no
output.

hwinfo --sound
16: PCI 100.1: 0403 Audio device                                
  [Created at pci.378]
  Unique ID: NXNs.kIq1OGtUT+F
  Parent ID: _Znp.+eZipJdga28
  SysFS ID: /devices/pci0000:00/0000:00:02.0/0000:01:00.1
  SysFS BusID: 0000:01:00.1
  Hardware Class: sound
  Model: "nVidia GF108 High Definition Audio Controller"
  Vendor: pci 0x10de "nVidia Corporation"
  Device: pci 0x0bea "GF108 High Definition Audio Controller"
  SubVendor: pci 0x10b0 "CardExpert Technology"
  SubDevice: pci 0x0f00 
  Revision: 0xa1
  Driver: "snd_hda_intel"
  Driver Modules: "snd_hda_intel"
  Memory Range: 0xfea7c000-0xfea7ffff (rw,non-prefetchable)
  IRQ: 19 (350893 events)
  Module Alias: "pci:v000010DEd00000BEAsv000010B0sd00000F00bc04sc03i00"
  Driver Info #0:
    Driver Status: snd_hda_intel is active
    Driver Activation Cmd: "modprobe snd_hda_intel"
  Config Status: cfg=yes, avail=yes, need=no, active=unknown
  Attached to: #19 (PCI bridge)

17: PCI 14.2: 0403 Audio device
  [Created at pci.378]
  Unique ID: 5Dex.Llr7zS2YqdE
  SysFS ID: /devices/pci0000:00/0000:00:14.2
  SysFS BusID: 0000:00:14.2
  Hardware Class: sound
  Model: "ATI SBx00 Azalia (Intel HDA)"
  Vendor: pci 0x1002 "ATI Technologies Inc"
  Device: pci 0x4383 "SBx00 Azalia (Intel HDA)"
  SubVendor: pci 0x1043 "ASUSTeK Computer Inc."
  SubDevice: pci 0x836c "M4A785TD Motherboard"
  Driver: "snd_hda_intel"
  Driver Modules: "snd_hda_intel"
  Memory Range: 0xfcff4000-0xfcff7fff (rw,non-prefetchable)
  IRQ: 16 (2322 events)
  Module Alias: "pci:v00001002d00004383sv00001043sd0000836Cbc04sc03i00"
  Driver Info #0:
    Driver Status: snd_hda_intel is active
    Driver Activation Cmd: "modprobe snd_hda_intel"
  Config Status: cfg=yes, avail=yes, need=no, active=unknown