A display controller for a data processing system includes a memory read sub-system operable to read data of input surfaces to be used as input layers to be processed by the display controller.The memory read sub-system is operable to request in advance the loading of memory address translation data into a memory address translation data cache for memory pages storing data relating to an input surface. The memory read sub-system selects the memory pages that it requests the advance loading of address translation data for based on information relating to the data for the input surface that will be required by the display controller to generate the output surface, such as the vertical and horizontal size of the input layer that the input surface will be used for, an indication of any flipping or rotation of the input surface, etc.