  Recently BICEP2 found that the vanishing of the tensor-to-scalar ratio $r$ is
excluded at $7\sigma$ level, and its most likely value is
$r=0.2^{+0.07}_{-0.05}$ at $1 \sigma$ level. This immediately causes a tension
with the Planck constraint $r < 0.11$. In addition, it also implies that the
inflaton (in single field slow-roll inflation) experienced a Planck excursion
during inflation $\Delta\phi /M_{Pl} \geq {\cal{O}}(1)$, whereby the effective
theory of inflation becomes questionable. In this brief report, we show that
the inflationary paradigm is still robust, even after the quantum effects are
taken into account. Moreover, these effects also help to relax the tension on
the different values of $r$ given by BICEP2 and Planck.
