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. Here is the output of "lspci | grep HCI" command: 00:1d.0 USB Controller: Intel Corp. 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #1 (rev 02) 00:1d.1 USB Controller: Intel Corp. 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #2 (rev 02) 00:1d.2 USB Controller: Intel Corp. 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #3 (rev 02) 00:1d.7 USB Controller: Intel Corp. 82801DB/DBM (ICH4/ICH4-M) USB2 EHCI Controller (rev 02) Regards, Sreevidya 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
