Lost sound upgrading to kernel 5.7.0-1-amd64 on Debian testing

[Eric S Fraga <e.fraga@ucl.ac.uk>]

Just a heads up: yesterday, I decided to upgrade all of my packages.  I
know: what a silly thing to do when having the computer working is
critical for work.  Anyway...

My system is mostly Debian testing (with a couple of bits from sid).  In
upgrading, I lost sound completely.  I spent a few hours trying to sort
this out, playing with pulseaudio, alsamixer, ...  Eventually, I
rebooted with the older kernel (version 5.6.0-1-amd64) which sorted
(some) things out.  I have sound again although only through my HDMI
display, not through the headphones, but that's enough for now.

-- 
Eric S Fraga via Emacs 28.0.50 & org 9.3.7 on Debian bullseye/sid