Once FE_SET_PROPERTY is called, the frontend will run a kernel thread that will periodically check for the tuner lock status and provide statistics about the quality of the signal.
The information about the frontend tuner locking status can be queried using ioctl FE_READ_STATUS.
Signal statistics are provided via ioctl FE_SET_PROPERTY, FE_GET_PROPERTY.
Note
Most statistics require the demodulator to be fully locked (e. g. with FE_HAS_LOCK bit set). See Frontend statistics indicators for more details.