Hi Bjorn and thank you very much for your kindness, attention and reply! Yes - I tested the all three ports of the device, even because my understanding of the Windows INF files is very primitive! And yes - I have verified that the device doesn't correspond to any of the goby layouts, even if I would like more opinions on this. I', a newbie in USB reverse engineering, if we can define it this way! :) both the true MODEM and management ports are working as expected, and also the NMEA is. Infact, I got voice audio from that port. You can also empirically get the signal with aplay and some exoteric settings. then the next topic - QMI. I was already thinking of it, but wanted to try to do the work in a different time frame. So: we're mapping interfaces 0, 2, 3 and 4. The missing interface 1 remains out, and I was thinking it's QMI, as is the case of Huawei E173. This doesn't impress me so much, since you can see traces of a primitive Huawei design looking at the command-set and in some comments in the inf files. another thing that makes me think it would be QMI, is the following answer from the device: Command: at+msmtype Answer: MSM90VO 1 [Feb 04 2008 05:00:00] And I remember QMI was adopted in MSM series. So I tried modifying the qmi_wwan.c driver in a rudimentary way to test this out. ... {QMI_FIXED_INTF(0x05c6, 0x0023, 1)}, ... But, the driver probe fails with the following error: [272967.950680] qmi_wwan: probe of 2-2:1.1 failed with error -22 [272967.951911] usbcore: registered new interface driver qmi_wwan And I don't know how to move on. What is the meaning of the -22 error? I was remembering somehow a "Resource is busy" kind of error, but, looking at what libusb tells: bus=2, addr=15, idVendor=05c6, idProduct=0023 interface 0: kernel driver active //qcserial interface 1: no active driver interface 2: kernel driver active //qcserial interface 3: kernel driver active //qcserial interface 4: kernel driver active //usb-storage (mmc + cd-rom) Might be this is not QMI? I don't think it's CDC, but I send here the lsusb -vv output: Bus 002 Device 015: ID 05c6:0023 Qualcomm, Inc. Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 1.10 bDeviceClass 0 (Defined at Interface level) bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 64 idVendor 0x05c6 Qualcomm, Inc. idProduct 0x0023 bcdDevice 0.00 iManufacturer 1 3G USB Modem ?? iProduct 2 (error) iSerial 4 000000000002 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 131 bNumInterfaces 5 bConfigurationValue 1 iConfiguration 0 bmAttributes 0xa0 (Bus Powered) Remote Wakeup MaxPower 500mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 3 bInterfaceClass 255 Vendor Specific Class bInterfaceSubClass 255 Vendor Specific Subclass bInterfaceProtocol 255 Vendor Specific Protocol iInterface 3 3G Devices Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0010 1x 16 bytes bInterval 128 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x82 EP 2 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0040 1x 64 bytes bInterval 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x02 EP 2 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0040 1x 64 bytes bInterval 0 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 1 bAlternateSetting 0 bNumEndpoints 2 bInterfaceClass 255 Vendor Specific Class bInterfaceSubClass 255 Vendor Specific Subclass bInterfaceProtocol 255 Vendor Specific Protocol iInterface 3 3G Devices Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x84 EP 4 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0040 1x 64 bytes bInterval 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x04 EP 4 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0040 1x 64 bytes bInterval 0 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 2 bAlternateSetting 0 bNumEndpoints 2 bInterfaceClass 255 Vendor Specific Class bInterfaceSubClass 255 Vendor Specific Subclass bInterfaceProtocol 255 Vendor Specific Protocol iInterface 3 3G Devices Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x86 EP 6 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0040 1x 64 bytes bInterval 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x06 EP 6 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0040 1x 64 bytes bInterval 0 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 3 bAlternateSetting 0 bNumEndpoints 2 bInterfaceClass 255 Vendor Specific Class bInterfaceSubClass 255 Vendor Specific Subclass bInterfaceProtocol 255 Vendor Specific Protocol iInterface 3 3G Devices Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x89 EP 9 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0040 1x 64 bytes bInterval 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x09 EP 9 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0040 1x 64 bytes bInterval 0 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 4 bAlternateSetting 0 bNumEndpoints 2 bInterfaceClass 8 Mass Storage bInterfaceSubClass 6 SCSI bInterfaceProtocol 80 Bulk-Only iInterface 3 3G Devices Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x83 EP 3 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0040 1x 64 bytes bInterval 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x08 EP 8 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0040 1x 64 bytes bInterval 0 Device Status: 0x0000 (Bus Powered) -- 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