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?
The application we are using is the zero gadget driver, for testing our host. 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? The host controller that we are using is Synopsys EHCI controller. rgds Juhee -----Original Message----- From: Alan Stern [mailto:[EMAIL PROTECTED] Sent: Tuesday, May 09, 2006 8:10 PM To: Juhee MALA Cc: linux-usb-devel@lists.sourceforge.net Subject: Re: [linux-usb-devel] USB Host performance On Tue, 9 May 2006, Juhee MALA wrote: > We are using Linux USB Host stack and doing some performance analysis. > For performance analysis we are testing it with a device, which > accepts the Bulk-OUT packets with full effieciency (not much-NYTES > from device side). We are submitting the data of URB size 8kbytes. The > throughput in such scenario that we are getting is approximately > 175Mbps. > > 1. Can anybody tell me, if this is a good performance? Good for what? It's certainly not the best possible. But it's more than adequate for USB-audio. > 2. Can anybody tell me what is the best performance that can be > achieved on a USB host? The maximum theoretical throughput for high-speed 512-byte bulk transfers is 13 packets per microframe, or 53248000 B/s. That's equivalent to 426 million bits per second. Linux can achieve such rates, if the hardware allows. To reach it, you have to submit a lot of URBs asynchronously. If you're using 8 KB transfer lengths then you should submit at least two batches of URBs, with at least 64 URBs in each batch, and with the URB_NO_INTERRUPT flag set on each URB except the last one in a batch. Each time a batch completes, immediately submit another batch. > 3. IS there any bench marking tool for checking the host stack > performance? Not that I know of. > 4. Which application should be used for demonstrating the host > performance? This is almost the same question as number 3. If you want to use your test device, you should select an application that will work with it. Of course, since I don't know what your test device is, I can't recommend any applications. 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&kid0709&bid&3057&dat1642 _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
