Redmi红米Note7和Note7 pro打开高通端口的方法open diag 9091， modem，rmnet。。。

Redmi Note7 & Note7 pro open diag & rmnet etc。。。
in some case, you may need this:

first，unlock the devices ，install TWRP and magisk

adb shell
su
mount -o rw,remount /system
cp  /system/build.prop /sdcard/
exit
exit
adb pull /sdcard/build.prop

then modify build.prop,
add or modify this two lines:

ro.fota.oem=
ro.debuggable=1

then put it back.

adb push build.prop /sdcard/
adb shell
su
mv -f  /sdcard/build.prop  /system/build.prop 
chmod 644 /system/build.prop 
chcon u:object_r:system_file:s0 /system/build.prop 
chown 0.0 /system/build.prop 
setprop persist.vendor.usb.config diag,serial_cdev,rmnet,adb
setprop persist.sys.usb.config diag,serial_cdev,rmnet,adb

then you will got diag 9091 & modem & net & adb port open…

hope this would help…