The UART DMA doesn't work which becomes a problem at baudrates higher than 3Mbits/s. The reason it fails is because the platform is suppose to provide DMA info to the uart-pl011 driver but it just passes it NULL. In arch/arm/mach-bcm2708/bcm2708.c line 242: "AMBA_DEVICE(uart0, "dev:f1", UART0, NULL);"
The last parameter of AMBA_DEVICE should be a pointer to a "struct amba_pl011_data" that is defined in include/linux/amba/serial.h line 201.
Does anyone know to write the dma_filter_fn function and whether or not dma polling should be enabled or not?