kselftest: cpufreq: Backup and restore governor for sptests

After executing cpufreq sptest, the system governor
will be overwritten with the governor switched
during the test. Restore this setting to maintain
consistency before and after the test.

Signed-off-by: Yiwei Lin <s921975628@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://patch.msgid.link/20260707163647.6646-1-s921975628@gmail.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

2 files changed, 35 insertions, 0 deletions

diff --git a/tools/testing/selftests/cpufreq/governor.sh b/tools/testing/selftests/cpufreq/governor.sh
index 212ef1cf43d5..cf59e63f8e14 100755
--- a/tools/testing/selftests/cpufreq/governor.sh
+++ b/tools/testing/selftests/cpufreq/governor.sh
@@ -16,6 +16,12 @@ source cpufreq.sh
 CUR_GOV=
 CUR_FREQ=
 
+# Per-policy backup, keyed by policy so multiple policies can be saved at once
+# (backup_governor/restore_governor also keep CUR_GOV/CUR_FREQ for callers that
+# read them directly).
+declare -A SAVED_GOVERNORS
+declare -A SAVED_FREQS
+
 # Find governor's directory path
 # $1: policy, $2: governor
 find_gov_directory()
@@ -39,11 +45,13 @@ find_current_governor()
 backup_governor()
 {
 	CUR_GOV=$(find_current_governor $1)
+	SAVED_GOVERNORS[$1]=$CUR_GOV
 
 	printf "Governor backup done for $1: $CUR_GOV\n"
 
 	if [ $CUR_GOV == "userspace" ]; then
 		CUR_FREQ=$(find_current_freq $1)
+		SAVED_FREQS[$1]=$CUR_FREQ
 		printf "Governor frequency backup done for $1: $CUR_FREQ\n"
 	fi
 
@@ -53,11 +61,13 @@ backup_governor()
 # $1: policy
 restore_governor()
 {
+	CUR_GOV=${SAVED_GOVERNORS[$1]}
 	__switch_governor $1 $CUR_GOV
 
 	printf "Governor restored for $1 to $CUR_GOV\n"
 
 	if [ $CUR_GOV == "userspace" ]; then
+		CUR_FREQ=${SAVED_FREQS[$1]}
 		set_cpu_frequency $1 $CUR_FREQ
 		printf "Governor frequency restored for $1: $CUR_FREQ\n"
 	fi
@@ -65,6 +75,17 @@ restore_governor()
 	printf "\n"
 }
 
+# Save/restore governors for every policy at once
+save_all_governors()
+{
+	for_each_policy backup_governor
+}
+
+restore_all_governors()
+{
+	for_each_policy restore_governor
+}
+
 # param:
 # $1: policy, $2: governor
 __switch_governor()
diff --git a/tools/testing/selftests/cpufreq/special-tests.sh b/tools/testing/selftests/cpufreq/special-tests.sh
index f45eb525f3b1..e87ed7c8e5e5 100755
--- a/tools/testing/selftests/cpufreq/special-tests.sh
+++ b/tools/testing/selftests/cpufreq/special-tests.sh
@@ -40,7 +40,9 @@ simple_lockdep()
 {
 	printf "** Test: Running ${FUNCNAME[0]} **\n"
 
+	save_all_governors
 	for_each_policy __simple_lockdep
+	restore_all_governors
 }
 
 # Test 2
@@ -56,7 +58,10 @@ concurrent_lockdep()
 {
 	printf "** Test: Running ${FUNCNAME[0]} **\n"
 
+	save_all_governors
 	for_each_policy_concurrent __concurrent_lockdep
+	wait
+	restore_all_governors
 }
 
 # Test 3
@@ -68,17 +73,23 @@ quick_shuffle()
 		echo ondemand | tee $CPUFREQROOT/policy*/scaling_governor &
 		echo userspace | tee $CPUFREQROOT/policy*/scaling_governor &
 	done
+	wait
 }
 
 governor_race()
 {
 	printf "** Test: Running ${FUNCNAME[0]} **\n"
 
+	save_all_governors
+
 	# run 8 concurrent instances
 	for I in `seq 8`
 	do
 		quick_shuffle &
 	done
+	wait
+
+	restore_all_governors
 }
 
 # Test 4
@@ -112,5 +123,8 @@ hotplug_with_updates_cpu()
 
 hotplug_with_updates()
 {
+	save_all_governors
 	for_each_non_boot_cpu hotplug_with_updates_cpu
+	wait
+	restore_all_governors
 }