On Mon, May 13, 2013 at 12:58 PM, Frederik Schmid <frederik.schmid@xxxxxxxxx> wrote: > Ming, > > The ehci controller is bogged down because the frames from the camera and > other stuff are being relayed over ethernet. If you mean usb camera and usb ethernet need to be used at the same time, it might be a problem, suppose your camera runs at the high bandwidth(3*1024/uframe), so the streaming speed is 24MByte/sec, and USB ethernet interface(100M) can't send the streaming data out as quickly as the camera. But if you plan to connect your usb camera onto musb, it is still not a good idea since musb can't give a good user experience to do periodic transfer, since CPU may not handle IRQ very quickly(it is often to see interrupt disabled for more than 1 millisecond on OMAP4 sometime), so the period of Isochronous transfer can't be set very much(1ms/period and less may not run well), otherwise streaming packets are dropped frequently by musb hardware even though you enable double buffer mode. So why don't you choose to connect your camera onto EHCI, and ethernet interface onto musb? 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
