Oliver, I made additional tests: made a clean compilation of 2.6.29.1 with CONFIG_USB_DEBUG=y , but the dmesg output is the same. Strangely enough, I compiled 2.6.24.7, and got the same results (the communication hangs at the poll() call), on the same machine. This is despite the fact that when running the same application on an ubuntu 8.04, it runs fine, which reports a kernel version of 2.6.24-23-generic. one interesting message I get on the console when plugging in the device is: drivers/usb/class/cdc-acm.c: This device cannot do calls on its own. It is no modem. the dmesg output for 2.6.29.1 when inserting the device is: Apr 22 14:08:19 tomodachi kernel: [ 259.088065] usb 2-1: new full speed USB device using uhci_hcd and address 2 Apr 22 14:08:19 tomodachi kernel: [ 259.245307] usb 2-1: New USB device found, idVendor=ffff, idProduct=0005 Apr 22 14:08:19 tomodachi kernel: [ 259.245312] usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3 Apr 22 14:08:19 tomodachi kernel: [ 259.245316] usb 2-1: Product: USBSerial Apr 22 14:08:19 tomodachi kernel: [ 259.245319] usb 2-1: Manufacturer: LPCUSB Apr 22 14:08:19 tomodachi kernel: [ 259.245322] usb 2-1: SerialNumber: DEADC0DE Apr 22 14:08:19 tomodachi kernel: [ 259.245842] usb 2-1: configuration #1 chosen from 1 choice Apr 22 14:08:19 tomodachi kernel: [ 259.294225] cdc_acm 2-1:1.0: ttyACM0: USB ACM device Apr 22 14:08:19 tomodachi kernel: [ 259.297156] usbcore: registered new interface driver cdc_acm Apr 22 14:08:19 tomodachi kernel: [ 259.297162] cdc_acm: v0.26:USB Abstract Control Model driver for USB modems and ISDN adapters for 2.6.24.7, it is: Apr 22 14:13:47 tomodachi kernel: [ 181.049644] usb 2-1: new full speed USB device using uhci_hcd and address 2 Apr 22 14:13:47 tomodachi kernel: [ 181.210892] usb 2-1: configuration #1 chosen from 1 choice Apr 22 14:13:47 tomodachi kernel: [ 181.213045] usb 2-1: Product: USBSerial Apr 22 14:13:47 tomodachi kernel: [ 181.213047] usb 2-1: Manufacturer: LPCUSB Apr 22 14:13:47 tomodachi kernel: [ 181.213050] usb 2-1: SerialNumber: DEADC0DE Apr 22 14:13:48 tomodachi kernel: [ 181.240322] cdc_acm 2-1:1.0: ttyACM0: USB ACM device Apr 22 14:13:48 tomodachi kernel: [ 181.243117] usbcore: registered new interface driver cdc_acm Apr 22 14:13:48 tomodachi kernel: [ 181.243127] drivers/usb/class/cdc-acm.c: v0.25:USB Abstract Control Model driver for USB modems and ISDN adapters what could be the problem? Akos -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
