On Wed, 10 May 2006, Juhee MALA wrote: > Hello Allan, > > Thanks for your answers. Just one question, when we use the URB_NO_INTERRUPT > flag, does it inhibit the interrrupt for non-error completions only? or does > it inhbit all the interrupts? If it inhibits all the interrupts how can we > monitor the status?
It inhibits normal completion interrupts only; error interrupts will still occur. > The application we are using is the zero gadget driver, for testing our > host. That is not an application; it is a driver. It runs on the device, not on the host. And it does not run at the maximum possible device speed. > Actually I just wanted to know what is the maximum speed that anybody > would have seen with the URB size of 8KByte, or is the theoretical value > actually achievable? I don't know what is the maximum speed anybody has ever seen (with any URB size, not just 8 KB). In fact, probably _nobody_ knows the maximum speed ever seen. And I doubt very much that the theoretical value is achievable with real hardware, outside of a laboratory setting. > One starnge thing that I see on the protocol Analyser is that,even within a > URB after we receive the ACK for one OUT packet the host sends the next OUT > packet after 4-5 microseconds (and I suppose that this is due to some > hardware latency, as software has no controller once the URB i submitted). > > Now if we consider this 4microsecond then time to transmit one packet of 512 > byte is approximately 14microseconds. Which means a throughput of > approximately 292Mbps. > > So to me it seems theat this is the maximum that I could achieve, even if I > remove my all software latencies. > > Can anybody tell me the reason for this 4-5microescond, time. Or is there > any way to remove this Since you already know it is a hardware latency you should be asking the people who designed the hardware, not us. Alan Stern ------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
