Lenovo P50 headphone issue

[Fabio Coatti]

Hi All,
I'm experiencing issues with a Lenovo P50 regarding headphones. It has
some similarities with the issue fixed in 5.8.13 with
commit ad0643252831ede7d6ab7b70a4f03768e032e6b4
Author: Hui Wang <hui.wang@xxxxxxxxxxxxx>
Date:   Mon Sep 14 14:51:18 2020 +0800

    ALSA: hda/realtek - Couldn't detect Mic if booting with headset plugged

I've been seeing this behavior since some time and now I'm running 5.8.14
Description: sometimes when I start the laptop with headphones plugged
in, no sound comes out of the headphones. The only thing I can hear is
the "usual" click when the kernel boots. Sound config in the gui
reports headphones plugged, nothing seems really wrong but no sound.
Removing headphones does not help: sound can be heard from laptop
loudspeakers but  to get back the sound on headphones I have to unplug
the jack, reboot the laptop and once booted, inserting the headphones
makes everything work as  expected. Gui tools report everything as
expected: headphones inserted, volume is ok and so on.
Below you can find the dmesg boot messages related to sound devices.
If you need more details please let me know.
If I picked the wrong address to report the issue please let me know,
I'll try to contact the relevant sources.
Please note that I'm not subscribed to this list even though I monitor
it, so being in CC: will be really appreciated.
Many thanks for any answer.
[Fri Oct  9 08:20:05 2020] snd_hda_codec_realtek hdaudioC0D0:
autoconfig for ALC298: line_outs=1 (0x14/0x0/0x0/0x0/0x0) type:speaker
[Fri Oct  9 08:20:05 2020] snd_hda_codec_realtek hdaudioC0D0:
speaker_outs=0 (0x0/0x0/0x0/0x0/0x0)
[Fri Oct  9 08:20:05 2020] snd_hda_codec_realtek hdaudioC0D0:
hp_outs=2 (0x17/0x21/0x0/0x0/0x0)
[Fri Oct  9 08:20:05 2020] snd_hda_codec_realtek hdaudioC0D0:    mono:
mono_out=0x0
[Fri Oct  9 08:20:05 2020] snd_hda_codec_realtek hdaudioC0D0:    inputs:
[Fri Oct  9 08:20:05 2020] snd_hda_codec_realtek hdaudioC0D0:      Mic=0x18
[Fri Oct  9 08:20:05 2020] snd_hda_codec_realtek hdaudioC0D0:      Dock Mic=0x19
[Fri Oct  9 08:20:05 2020] snd_hda_codec_realtek hdaudioC0D0:
Internal Mic=0x12
[Fri Oct  9 08:20:05 2020] videodev: Linux video capture interface: v2.00
[Fri Oct  9 08:20:05 2020] input: HDA NVidia HDMI/DP,pcm=3 as
/devices/pci0000:00/0000:00:01.0/0000:01:00.1/sound/card1/input15
[Fri Oct  9 08:20:05 2020] input: HDA NVidia HDMI/DP,pcm=7 as
/devices/pci0000:00/0000:00:01.0/0000:01:00.1/sound/card1/input16
[Fri Oct  9 08:20:05 2020] input: HDA NVidia HDMI/DP,pcm=8 as
/devices/pci0000:00/0000:00:01.0/0000:01:00.1/sound/card1/input17
[Fri Oct  9 08:20:05 2020] input: HDA NVidia HDMI/DP,pcm=9 as
/devices/pci0000:00/0000:00:01.0/0000:01:00.1/sound/card1/input18
[Fri Oct  9 08:20:05 2020] input: HDA NVidia HDMI/DP,pcm=10 as
/devices/pci0000:00/0000:00:01.0/0000:01:00.1/sound/card1/input19
[Fri Oct  9 08:20:05 2020] input: HDA NVidia HDMI/DP,pcm=11 as
/devices/pci0000:00/0000:00:01.0/0000:01:00.1/sound/card1/input20
[Fri Oct  9 08:20:05 2020] input: HDA Intel PCH Mic as
/devices/pci0000:00/0000:00:1f.3/sound/card0/input22
[Fri Oct  9 08:20:05 2020] input: HDA Intel PCH Dock Mic as
/devices/pci0000:00/0000:00:1f.3/sound/card0/input23
[Fri Oct  9 08:20:05 2020] input: HDA Intel PCH Dock Headphone as
/devices/pci0000:00/0000:00:1f.3/sound/card0/input24
[Fri Oct  9 08:20:05 2020] input: HDA Intel PCH Headphone as
/devices/pci0000:00/0000:00:1f.3/sound/card0/input25
--
Fabio