This is my complete queue fo the omap serial driver based on the 8250 core code. I played with it on beagle bone, am335x-evm and dra7xx including DMA. The uncertain remain the runtime-pm pieces. I hacked a small serial testing application which sent 10x 4KiB of data in raw mode. The number of interrupts in comparison: serial-omap | 8250 omap | 8250 omap + dma | -------------------------------------------- TX | 2558 | 641 | 0 + 30 | RX | 40960 | 854 | 1 + 853 | So the 8250 version uses less interrupts for the same amount of data. The consequence is that in TX mode there should be "short" periods where no data is sent (before the CPU gets to re-fill the FIFO). On RX we have a smaller time frame where we have to start to purge the FIFO before it overflows. Sebastian -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html