1. A method of adjusting a voltage supplied to a first electronic device, said first electronic device coupled to a second electronic device via a wired communication link, comprising: determining a performance metric of the first electronic device in accordance with signals received by the first electronic device from the second electronic device via the wired communication link; comparing the performance metric with a first threshold value and comparing the performance metric with a second threshold value; increasing the voltage if the performance metric differs from the first threshold value in a first direction; and decreasing the voltage if the performance metric differs from the second threshold value in a second direction that is opposite to the first direction.