This patchset tries to loose the check on DMA buffer size in check_unmap() of dma-debug first, then only unmap the actual completed DMA buffer in USB unmap path. Considered that DMA unmapping often runs in hard irq context, the patch set may save irq handling time. And the improvement can be observed on ARMv7(Pandaboard) with the chage, at average ~25us is saved about ehci irq handling under usbnet ping test case. Thanks, -- Ming Lei -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html