This paper proposes a joint packet scheduling and computation offloading policy for an Energy Harvesting (EH) mobile terminal wirelessly connected to a Base Station (BS) when the channel between the mobile and the BS is unavailable at the mobile side. The mobile terminal has to decide if its packet related to one application is computed either locally or remotely by the BS within a strict delay imposed by this application without knowing the channel in advance. Our objective is to guarantee reliable communication by minimizing the packet loss. This packet loss is due to buffer overflow, strict delay violation and channel mismatch. We formulate the problem using a Markov Decision Process (MDP) and we propose and implement the optimal deterministic offline policy to solve it. This optimal policy decides: (i) the execution location (locally or remotely), (ii) the number of packets to be executed and (iii) the corresponding transmission power. This policy offers a dramatic increase in the number of executed packets and a significant energy saving.