Audio was working previously. In settings>sound, it shows "Dummy output".
No card is shown.
$ pacmd list-cards 0 card(s) available.
Although device is shown
$ lspci -nnk | grep -A2 Audio 00:1f.3 Audio device : Intel Corporation Sunrise Point-LP HD Audio [8086:9d71] (rev 21) Subsystem: Hewlett-Packard Company Sunrise Point-LP HD Audio [103c:832b] Kernel driver in use: snd_hda_intel Kernel modules: snd_hda_intel, snd_soc_skl
No audio with headphone/earphone as well. It might be relevant that the problem occured when I was trying to fix bluetooth audio problem using this link -
Although I edited /etc/modprobe.d/alsa-base.conf by appending 'options snd-hda-intel model=generic' at the end, I removed it afterwards but still the problem persisted. I don't know exactly what trigerred the problem.
Also, There is no option for audio devices in BIOS (My laptop model is HP 15bs180tx) as suggested by "Joel Kleier's" answer to -