In one embodiment, a user of a mobile device comprising a front-side display and a back-side touch surface selects a control key mode for an application user interface displayed in the front-side display by using touch input on the back-side touch surface. A congestion control parameter value to be used to schedule a storage operation corresponding to the IO request is determined. The metal oxide layer itself can be used as a textured structure pattern, or the textured structure pattern can be formed by forming holes in the substrate or a material layer under the metal oxide layer corresponding to the holes of the metal oxide layer. A motor control module may receive a signal from the control logic module, apply the chosen set of parameters to driving the camera motor, and command the motor driver circuit to drive the motor in accordance with the applied set of parameters. Also, when the seat is not in the workstation position, a second seat can be detachably fixed in the workstation position. This approach is well suited for use in connection with portable devices that use voice command interfaces.