Re: code review request: simple usb stream interface (susi)
Edwin Olson <[email protected]>
| Newsgroups | gmane.linux.usb.devel |
|---|---|
| Message-ID | <[email protected]> |
>> Hmm, I've implemented the multiple outstanding URBs, but it appears that >> my host only considers one read URB per 1ms period, no matter how many >> read URBs have been submitted. >> > > What host controller driver are you using? It's an ICH8 (P965), and I /proc/bus/usb/devices says it's connected to a uhci_hcd. 00:1a.0 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI #4 (rev 02) 00:1a.1 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI #5 (rev 02) 00:1a.7 USB Controller: Intel Corporation 82801H (ICH8 Family) USB2 EHCI #2 (rev 02) > So I see. Do you happen to have the URB_NO_FSBR flag turned on in your > URBs? Not in my code, at least... What does it do? > Have you tried using a USB bus analyzer to find out what's really > happening? I wish I had one! More testing seems to indicate that multiple outstanding URBs does make a very small (10%?) difference in performance, and staring at usbmon, it appears that sometimes I do in fact get multiple callbacks from the same frame. But it's quite rare... -Ed ------------------------------------------------------------------------- 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 _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel