On Tue, 27 Jun 2006 [EMAIL PROTECTED] wrote: > Hi, > > I am new to USB device drivers. > I am working on an application which talks to USB modems ( CDC devices). > The driver being used is usbserial with some modifications to suit the > application. > The devices are connected to the Linux system(kernel -2.6.16.13) through > hubs. Both hubs and modems are USB 2.0 devices. > Hub is high speed device and modems are full speed devices. > When trying to communicate with the modems the following errors are > observed from the logs: > > device descriptor read/64, error -110 > khubd timed out on ep0in len=0/64 > khubd timed out on ep0out len=0/0 > device not accepting address 10, error -110 > > But when tried to use uhci_hcd driver instead of ehci_hcd driver, I was > able to communicate to the modems. > Can someone let me know the reason for different behavior with ehci_hcd > and uhci_hcd drivers. > Can't we use ehci_hcd with combination of high speed hub and full speed > device. > Please share your experience. > Please let me know if further information is required.
It's possible that the transaction translators in your hubs aren't working right. Normally people don't have these problems using ehci-hcd to communicate with full-speed devices behind high-speed hubs. (There are other problems, involving scheduling of periodic transactions, but they are different from what you saw.) 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 _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
