lib.sh: Reset ALSA settings at set_alsa()

Reset ALSA settings with `alsactl init` and `alsactl restore`
at `set_alsa()` before it calls `set_alsa_settings` which runs
HW model-specific configuration scripts.

This way a test case can expect that the `set_alsa` call will apply
the DUT's default ALSA settings as the baseline configuration
to avoid side-effects possible after the previous tests execution
(either passed, or failed) as well as other unexpected changes.

Signed-off-by: Dmitrii Golovanov <dmitrii.golovanov@intel.com>

Author: golowanow

case-lib/lib.sh

@@ -1249,6 +1249,22 @@ reset_sof_volume()
 
 set_alsa()
 {
+  local alsa_log="${LOG_ROOT}/alsa_setup.log"
+
+  dlogi "Try to initialize all devices to their default ALSA state (alsactl init)."
+  printf '%s\n' '-vv------- ALSA init -------vv-' > "${alsa_log}"
+  alsactl -d init >> "${alsa_log}" 2>&1 || rc=$?
+  [[ "${rc}" -ne 0 ]] && dlogw "alsactl init error=${rc}"
+  printf '%s\n' '-^^------- ALSA init -------^^-' >> "${alsa_log}"
+
+  dlogi "Restore ALSA defaults from /var/lib/alsa/asound.state"
+  printf '%s\n' '-vv------- Restore ALSA defaults -------vv-' >> "${alsa_log}"
+  # We don't need in sudo to write our alsa_log file, but to call `alsactl restore`.
+  # shellcheck disable=SC2024
+  sudo alsactl -d restore >> "${alsa_log}" 2>&1 || rc=$?
+  [[ "${rc}" -ne 0 ]] && dlogw "alsactl restore error=${rc}"
+  printf '%s\n' '-^^------- Restore ALSA defaults -------^^-' >> "${alsa_log}"
+
   reset_sof_volume
 
   # If MODEL is defined, set proper gain for the platform