First test with the latest kernel in the official repositories. ii linux-image-2.6.31-14-gen 2.6.31-14.48 Linux kernel image for version 2.6.31 on x86/x86_64 The modem is "visible" as a modem during one minute or two but then the device or the USB controller seems to trigger a reset. The device is then recognize as a USB mass storage for a few seconds. Kernel logs bellow. I will test now with the patch. [ 943.870064] usb 5-1: new full speed USB device using uhci_hcd and address 6 [ 944.093222] usb 5-1: configuration #1 chosen from 1 choice [ 944.097157] scsi21 : SCSI emulation for USB Mass Storage devices [ 944.097605] usb-storage: device found at 6 [ 944.097607] usb-storage: waiting for device to settle before scanning [ 944.472630] usb 5-1: USB disconnect, address 6 [ 944.752567] usb 5-1: new full speed USB device using uhci_hcd and address 7 [ 944.917223] usb 5-1: configuration #1 chosen from 1 choice [ 944.922277] option 5-1:1.0: GSM modem (1-port) converter detected [ 944.922360] usb 5-1: GSM modem (1-port) converter now attached to ttyUSB0 [ 944.924622] option 5-1:1.1: GSM modem (1-port) converter detected [ 944.924689] usb 5-1: GSM modem (1-port) converter now attached to ttyUSB1 [ 944.925402] scsi24 : SCSI emulation for USB Mass Storage devices [ 944.925521] usb-storage: device found at 7 [ 944.925523] usb-storage: waiting for device to settle before scanning [ 949.924260] usb-storage: device scan complete [ 949.927210] scsi 24:0:0:0: CD-ROM HUAWEI Mass Storage 2.31 PQ: 0 ANSI: 2 [ 949.949185] sr1: scsi-1 drive [ 949.949297] sr 24:0:0:0: Attached scsi CD-ROM sr1 [ 949.949359] sr 24:0:0:0: Attached scsi generic sg2 type 5 [ 962.300289] sr1: CDROM (ioctl) error, command: Get configuration 46 00 00 00 00 00 00 00 20 00 [ 962.300300] sr: Sense Key : No Sense [current] [ 962.300303] sr: Add. Sense: No additional sense information [ 962.505311] sr1: CDROM (ioctl) error, command: Get configuration 46 00 00 00 00 00 00 00 20 00 [ 962.505322] sr: Sense Key : No Sense [current] [ 962.505325] sr: Add. Sense: No additional sense information [ 962.585238] option: option_instat_callback: error -108 [ 962.585386] option1 ttyUSB0: GSM modem (1-port) converter now disconnected from ttyUSB0 [ 962.585407] option 5-1:1.0: device disconnected [ 962.585474] option1 ttyUSB1: GSM modem (1-port) converter now disconnected from ttyUSB1 [ 962.585490] option 5-1:1.1: device disconnected [ 962.700078] usb 5-1: reset full speed USB device using uhci_hcd and address 7 [ 962.850462] option 5-1:1.1: GSM modem (1-port) converter detected [ 962.850549] usb 5-1: GSM modem (1-port) converter now attached to ttyUSB0 [ 962.851334] option 5-1:1.0: GSM modem (1-port) converter detected [ 962.851402] usb 5-1: GSM modem (1-port) converter now attached to ttyUSB1 [ 963.248269] option: option_instat_callback: error -108 [ 963.249521] option1 ttyUSB1: GSM modem (1-port) converter now disconnected from ttyUSB1 [ 963.249537] option 5-1:1.0: device disconnected [ 963.249590] option1 ttyUSB0: GSM modem (1-port) converter now disconnected from ttyUSB0 [ 963.249604] option 5-1:1.1: device disconnected [ 963.372579] usb 5-1: reset full speed USB device using uhci_hcd and address 7 [ 963.441013] usb 5-1: USB disconnect, address 7 [ 963.441695] scsi 24:0:0:0: rejecting I/O to dead device [ 977.720437] usb 5-1: new full speed USB device using uhci_hcd and address 8 [ 977.884700] usb 5-1: configuration #1 chosen from 1 choice [ 977.889705] option 5-1:1.0: GSM modem (1-port) converter detected [ 977.889780] usb 5-1: GSM modem (1-port) converter now attached to ttyUSB0 [ 977.893896] option 5-1:1.1: GSM modem (1-port) converter detected [ 977.893977] usb 5-1: GSM modem (1-port) converter now attached to ttyUSB1 [ 977.904759] scsi29 : SCSI emulation for USB Mass Storage devices [ 977.911871] usb-storage: device found at 8 [ 977.911874] usb-storage: waiting for device to settle before scanning [ 982.911735] usb-storage: device scan complete [ 1004.042840] option: option_instat_callback: error -108 [ 1004.042976] option1 ttyUSB0: GSM modem (1-port) converter now disconnected from ttyUSB0 [ 1004.042994] option 5-1:1.0: device disconnected [ 1004.043052] option1 ttyUSB1: GSM modem (1-port) converter now disconnected from ttyUSB1 [ 1004.043067] option 5-1:1.1: device disconnected [ 1004.160082] usb 5-1: reset full speed USB device using uhci_hcd and address 8 [ 1004.321021] option 5-1:1.1: GSM modem (1-port) converter detected [ 1004.321096] usb 5-1: GSM modem (1-port) converter now attached to ttyUSB0 [ 1004.321408] option 5-1:1.0: GSM modem (1-port) converter detected [ 1004.321454] usb 5-1: GSM modem (1-port) converter now attached to ttyUSB1 [ 1004.346893] scsi 29:0:0:0: CD-ROM HUAWEI Mass Storage 2.31 PQ: 0 ANSI: 2 [ 1004.368873] sr1: scsi-1 drive [ 1004.368986] sr 29:0:0:0: Attached scsi CD-ROM sr1 [ 1004.369049] sr 29:0:0:0: Attached scsi generic sg2 type 5 [ 1016.301000] sr1: CDROM (ioctl) error, command: Get configuration 46 00 00 00 00 00 00 00 20 00 [ 1016.301011] sr: Sense Key : No Sense [current] [ 1016.301014] sr: Add. Sense: No additional sense information [ 1016.480988] sr1: CDROM (ioctl) error, command: Get configuration 46 00 00 00 00 00 00 00 20 00 [ 1016.480998] sr: Sense Key : No Sense [current] [ 1016.481002] sr: Add. Sense: No additional sense information [ 1016.577986] sr1: CDROM (ioctl) error, command: Get configuration 46 00 00 00 00 00 00 00 20 00 [ 1016.577998] sr: Sense Key : No Sense [current] [ 1016.578002] sr: Add. Sense: No additional sense information [ 1016.584979] sr1: CDROM (ioctl) error, command: Get configuration 46 00 00 28 00 00 00 00 10 00 [ 1016.584989] sr: Sense Key : No Sense [current] [ 1016.584992] sr: Add. Sense: No additional sense information [ 1016.592986] sr1: CDROM (ioctl) error, command: Get configuration 46 00 00 20 00 00 00 00 18 00 [ 1016.592997] sr: Sense Key : No Sense [current] [ 1016.593001] sr: Add. Sense: No additional sense information [ 1016.613985] sr1: CDROM (ioctl) error, command: Get configuration 46 00 00 00 00 00 00 00 20 00 [ 1016.613996] sr: Sense Key : No Sense [current] [ 1016.614000] sr: Add. Sense: No additional sense information [ 1016.625995] ISO 9660 Extensions: Microsoft Joliet Level 3 [ 1016.638964] option: option_instat_callback: error -108 [ 1016.639094] option1 ttyUSB1: GSM modem (1-port) converter now disconnected from ttyUSB1 [ 1016.639112] option 5-1:1.0: device disconnected [ 1016.639166] option1 ttyUSB0: GSM modem (1-port) converter now disconnected from ttyUSB0 [ 1016.639180] option 5-1:1.1: device disconnected [ 1016.750066] usb 5-1: reset full speed USB device using uhci_hcd and address 8 [ 1016.903174] option 5-1:1.1: GSM modem (1-port) converter detected [ 1016.903260] usb 5-1: GSM modem (1-port) converter now attached to ttyUSB0 [ 1016.903883] option 5-1:1.0: GSM modem (1-port) converter detected [ 1016.903946] usb 5-1: GSM modem (1-port) converter now attached to ttyUSB1 [ 1017.301969] option: option_instat_callback: error -108 [ 1017.303159] option1 ttyUSB1: GSM modem (1-port) converter now disconnected from ttyUSB1 [ 1017.303179] option 5-1:1.0: device disconnected [ 1017.303242] option1 ttyUSB0: GSM modem (1-port) converter now disconnected from ttyUSB0 [ 1017.303258] option 5-1:1.1: device disconnected [ 1017.420090] sr 29:0:0:0: [sr1] Unhandled error code [ 1017.420094] sr 29:0:0:0: [sr1] Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK [ 1017.420098] end_request: I/O error, dev sr1, sector 84 [ 1017.420120] usb 5-1: USB disconnect, address 8 [ 1017.420794] ISOFS: unable to read i-node block [ 1017.420800] isofs_fill_super: get root inode failed [ 1017.540086] usb 5-1: new full speed USB device using uhci_hcd and address 9 [ 1017.610105] hub 5-0:1.0: unable to enumerate USB device on port 1