  We provide an explicit method for solving general markovian master equations
for quadratic bosonic Hamiltonians with linear bath operators. As an example we
consider a one-dimensional quantum harmonic oscillator chain coupled to thermal
reservoirs at both ends of the chain. We derive an analytic solution of the
Redfield master equation for homogeneous harmonic chain and recover classical
results, namely, vanishing temperature gradient and constant heat current in
the thermodynamic limit. In the case of the disordered gapped chains we observe
universal heat current scaling independent of the bath spectral function, the
system-bath coupling strength, and the boundary conditions.
