  The puzzling mechanism of coherent radio emission remains unknown, but
fortunately, repeating fast radio bursts (FRBs) provide a precious opportunity,
with extremely bright subpulses created in a clear and vacuum-like pulsar
magnetosphere. FRBs are millisecond-duration signals that are highly dispersed
at distant galaxies but with uncertain physical origin(s). Coherent curvature
radiation by bunches has already been proposed for repeating FRBs. The charged
particles are created during central star's quakes, which can form bunches
streaming out along curved magnetic field lines, so as to trigger FRBs. The
nature of narrow-band radiation with time-frequency drifting can be a natural
consequence that bunches could be observed at different times with different
curvatures. Additionally, high linear-polarization can be seen if the line of
sight is confined to the beam angle, whereas the emission could be highly
circular-polarized if off-beam. It is also discussed that pulsar surface may be
full of small hills (i.e., zits) which would help producing bulk of energetic
bunches for repeating FRBs as well as for rotation-powered pulsars.
