The invention introduces a non-transitory computer program product for adjusting equalization when executed by a processing unit of a storage device. The non-transitory computer program product includes program code to: activate an eye-diagram analyzer to adjust a parameter of an equalizer according to magnitudes corresponding to an eye-diagram, which are generated by the eye-diagram analyzer, and repeatedly adjust a parameter of the equalizer after a symbol decoding error is detected until an adjustment failure is detected or successive waveforms output from the equalizer belong to an eye open state. The symbol decoding error is detected during a reception of host data from a host side according to a command issued by the host side, which is defined in Universal Flash Storage (UFS) specification.