mount -t debugfs none /sys/kernel/debug echo "file net/bluetooth/* +pfl" > /sys/kernel/debug/dynamic_debug/control ====== Enable pr_debug ====== CFLAGS += -DDEBUG=1 cp /lib/modules/$(uname -r)/build/.config . cp /lib/modules/$(uname -r)/build/Module.symvers . make oldconfig #make EXTRAVERSION=-my modules_prepare make modules_prepare make M=net/bluetooth sudo cp net/bluetooth/bluetooth.ko /lib/modules/`uname -r`/updates depmod -a sudo rmmod btusb btrtl btintel btbcm bnep btusb bluetooth modinfo bluetooth filename: /lib/modules/4.18.0-0.bpo.1-amd64/updates/bluetooth.ko ... sudo modprobe bluetooth