最近，我一直在尝试锁定CPU核心频率，以便在MTK 8050上进行性能测试。但是，修改CPU频率后，该值保持不变。手机已经拥有root权限。以下是一些详细信息

TECNO-CK9n:/sys/devices/system/cpu/cpufreq/policy4 # ls -l
total 0
-r--r--r-- 1 root   root   4096 2023-09-21 12:49 affected_cpus
-r-------- 1 root   root   4096 2023-09-21 12:49 cpuinfo_cur_freq
-r--r--r-- 1 root   root   4096 2023-09-21 12:45 cpuinfo_max_freq
-r--r--r-- 1 root   root   4096 2023-09-21 12:45 cpuinfo_min_freq
-r--r--r-- 1 root   root   4096 2023-09-21 12:49 cpuinfo_transition_latency
-r--r--r-- 1 root   root   4096 2023-09-21 12:49 related_cpus
-r--r--r-- 1 root   root   4096 2023-09-21 12:49 scaling_available_frequencies
-r--r--r-- 1 root   root   4096 2023-09-21 12:49 scaling_available_governors
-r--r--r-- 1 root   root   4096 2023-09-21 12:45 scaling_cur_freq
-r--r--r-- 1 root   root   4096 2023-09-21 12:49 scaling_driver
-rw-rw---- 1 system system 4096 2023-09-21 12:02 scaling_governor
-rw-rw-r-- 1 system system 4096 2023-09-20 21:15 scaling_max_freq
-rw-rw-r-- 1 system system 4096 2023-09-21 12:24 scaling_min_freq
-rw-r--r-- 1 root   root   4096 2023-09-21 12:51 scaling_setspeed
drwxr-xr-x 2 root   root      0 2023-09-21 12:45 stats
TECNO-CK9n:/sys/devices/system/cpu/cpufreq/policy4 # whoami
root
TECNO-CK9n:/sys/devices/system/cpu/cpufreq/policy4 # cat scaling_governor
userspace
TECNO-CK9n:/sys/devices/system/cpu/cpufreq/policy4 # cat scaling_available_frequencies
2600000 2507000 2354000 2200000 1985000 1855000 1740000 1624000 1537000 1451000 1335000 1162000 1046000 902000 700000 437000
TECNO-CK9n:/sys/devices/system/cpu/cpufreq/policy4 # echo 2600000 > scaling_setspeed
TECNO-CK9n:/sys/devices/system/cpu/cpufreq/policy4 # cat scaling_setspeed
700000
TECNO-CK9n:/sys/devices/system/cpu/cpufreq/policy4 #