alsa: Restore test settings after each test

Currently, some tests change ALSABAT settings
during their execution, but do not restore them
to their prior state.

This causes tests that occur later
in the execution order to intermittently fail.

To remedy this, all tests that use ALSA now use
a common save_alsa_state function, which shall
save current ALSA state to a file and then restore
that state on the bash script EXIT signal.

Signed-off-by: Lukasz Mrugala <lukaszx.mrugala@intel.com>

Author: LukaszMrugala

case-lib/hijack.sh

@@ -185,6 +185,11 @@ function func_exit_handler()
         fi
     }
 
+    # Restore ALSA settings after execution if state file exists
+    if [ -f "${SOF_TEST_ALSA_STATE_FILENAME}" ]; then
+        restore_alsa_state
+    fi
+
     print_test_result_exit $exit_status
 }
 

case-lib/lib.sh

@@ -8,6 +8,8 @@ SCRIPT_HOME=$(cd "$SCRIPT_HOME/.." && pwd)
 SCRIPT_NAME="$0"  # get test-case script load name
 # shellcheck disable=SC2034 # external script can use it
 SCRIPT_PRAM="$*"  # get test-case parameter
+# shellcheck disable=SC2034 # external script can use it
+SOF_TEST_ALSA_STATE_FILENAME=/tmp/"${SCRIPT_NAME##*/}".$$.state
 
 # Source from the relative path of current folder
 # shellcheck source=case-lib/config.sh
@@ -1187,3 +1189,27 @@ perf_analyze()
     fi
 }
 
+# Restore the machine state from a file.
+# Should be triggered at the end of
+# every test touching ALSA.
+# Couple with save_machine_state.
+restore_alsa_state()
+{
+    dlogi "restore_alsa_state called in ${SOF_TEST_ALSA_STATE_FILENAME}"
+    if [ -f "${SOF_TEST_ALSA_STATE_FILENAME}" ]; then
+        dlogi "restore_alsa_state found a relevant state file."
+        alsactl restore --file "${SOF_TEST_ALSA_STATE_FILENAME}" --pedantic --no-ucm --no-init-fallback || dlogi "alsactl state restoration failed!"
+        rm "${SOF_TEST_ALSA_STATE_FILENAME}" || dlogi "Old state file removal failed!"
+    fi
+}
+
+# Save the machine state to a file.
+# Should be used at the start of
+# every test touching ALSA.
+# Coupled with restore_machine_state
+# on an exit signal inside func_exit_handler.
+save_alsa_state()
+{
+    dlogi "save_alsa_state called in ${SOF_TEST_ALSA_STATE_FILENAME}"
+    alsactl store --file "${SOF_TEST_ALSA_STATE_FILENAME}" || dlogi "alsactl state storage failed!"
+}

test-case/check-alsabat.sh

@@ -74,6 +74,7 @@ sigmak=${OPT_VAL['k']}
 frames=${OPT_VAL['n']}
 
 start_test
+save_alsa_state
 
 if [ "$pcm_p" = "" ]||[ "$pcm_c" = "" ];
 then

test-case/check-audio-equalizer.sh

@@ -43,6 +43,7 @@ func_pipeline_export "$tplg" "eq:any"
 sofcard=${SOFCARD:-0}
 
 start_test
+save_alsa_state
 setup_kernel_check_point
 
 # Test equalizer

test-case/check-capture.sh

@@ -58,6 +58,7 @@ out_dir=${OPT_VAL['o']}
 file_prefix=${OPT_VAL['f']}
 
 start_test
+save_alsa_state
 logger_disabled || func_lib_start_log_collect
 
 setup_kernel_check_point

test-case/check-fw-echo-reference.sh

@@ -41,6 +41,7 @@ frames=${OPT_VAL['n']}
 frequency=${OPT_VAL['f']}
 
 start_test
+save_alsa_state
 logger_disabled || func_lib_start_log_collect
 
 func_pipeline_export "$tplg" "echo:any"

test-case/check-keyword-detection.sh

@@ -54,6 +54,7 @@ preamble_time=${OPT_VAL['p']}
 duration=${OPT_VAL['d']}
 
 start_test
+save_alsa_state
 logger_disabled || func_lib_start_log_collect
 
 func_pipeline_export "$tplg" "kpb:any"

test-case/check-kmod-load-unload-after-playback.sh

@@ -55,6 +55,7 @@ loop_cnt=${OPT_VAL['l']}
 pb_duration=${OPT_VAL['d']}
 
 start_test
+save_alsa_state
 
 func_pipeline_export "$tplg" "type:playback"
 

test-case/check-kmod-load-unload.sh

@@ -39,6 +39,7 @@ func_opt_parse_option "$@"
 setup_kernel_check_point
 
 start_test
+save_alsa_state
 
 loop_cnt=${OPT_VAL['l']}
 

test-case/check-pause-release-suspend-resume.sh

@@ -95,6 +95,7 @@ test_mode=${OPT_VAL['m']}
 file_name=${OPT_VAL['F']}
 
 start_test
+save_alsa_state
 
 case $test_mode in
     "playback")