  We consider coherent dynamics of graphene charged carriers exposed to an
intense few-cycle linearly polarized laser pulse. The results, obtained by
solving the generalized semiconductor Bloch equations numerically in the
Hartree-Fock approximation, taking into account many-body Coulomb interaction,
demonstrate strong dependence of the valley polarization on the
carrier-envelope phase (CEP), which is interpolated by the simple sinusoidal
law. Then we consider harmonic generation in multi-cycle laser field by
graphene preliminary exposed to an intense few-cycle laser pulse. We show that
the second harmonic's intensity is a robust observable quantity that provides a
gauge of CEP for pulse durations up to two optical cycles, corresponding to 40
$\mathrm{fs}$ at the wavelength of 6.2 $\mathrm{\mu m}$.
