Yes of course: Bus 003 Device 002: ID 046d:c52b Logitech, Inc. Unifying Receiver Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 2.00 bDeviceClass 0 bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 8 idVendor 0x046d Logitech, Inc. idProduct 0xc52b Unifying Receiver bcdDevice 12.01 iManufacturer 1 Logitech iProduct 2 USB Receiver iSerial 0 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 84 bNumInterfaces 3 bConfigurationValue 1 iConfiguration 4 RQR12.01_B0019 bmAttributes 0xa0 (Bus Powered) Remote Wakeup MaxPower 98mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 1 bInterfaceClass 3 Human Interface Device bInterfaceSubClass 1 Boot Interface Subclass bInterfaceProtocol 1 Keyboard iInterface 0 HID Device Descriptor: bLength 9 bDescriptorType 33 bcdHID 1.11 bCountryCode 0 Not supported bNumDescriptors 1 bDescriptorType 34 Report wDescriptorLength 59 Report Descriptors: ** UNAVAILABLE ** Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0008 1x 8 bytes bInterval 8 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 1 bAlternateSetting 0 bNumEndpoints 1 bInterfaceClass 3 Human Interface Device bInterfaceSubClass 1 Boot Interface Subclass bInterfaceProtocol 2 Mouse iInterface 0 HID Device Descriptor: bLength 9 bDescriptorType 33 bcdHID 1.11 bCountryCode 0 Not supported bNumDescriptors 1 bDescriptorType 34 Report wDescriptorLength 148 Report Descriptors: ** UNAVAILABLE ** Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x82 EP 2 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0008 1x 8 bytes bInterval 2 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 2 bAlternateSetting 0 bNumEndpoints 1 bInterfaceClass 3 Human Interface Device bInterfaceSubClass 0 bInterfaceProtocol 0 iInterface 0 HID Device Descriptor: bLength 9 bDescriptorType 33 bcdHID 1.11 bCountryCode 0 Not supported bNumDescriptors 1 bDescriptorType 34 Report wDescriptorLength 98 Report Descriptors: ** UNAVAILABLE ** Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x83 EP 3 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0020 1x 32 bytes bInterval 2 can't get device qualifier: Resource temporarily unavailable can't get debug descriptor: Resource temporarily unavailable Device Status: 0x0000 (Bus Powered) Bus 003 Device 003: ID 046d:c52e Logitech, Inc. MK260 Wireless Combo Receiver Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 2.00 bDeviceClass 0 bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 8 idVendor 0x046d Logitech, Inc. idProduct 0xc52e MK260 Wireless Combo Receiver bcdDevice 15.00 iManufacturer 1 Logitech iProduct 2 USB Receiver iSerial 0 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 59 bNumInterfaces 2 bConfigurationValue 1 iConfiguration 4 RQR15.00_B0048 bmAttributes 0xa0 (Bus Powered) Remote Wakeup MaxPower 98mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 1 bInterfaceClass 3 Human Interface Device bInterfaceSubClass 1 Boot Interface Subclass bInterfaceProtocol 1 Keyboard iInterface 0 HID Device Descriptor: bLength 9 bDescriptorType 33 bcdHID 1.11 bCountryCode 0 Not supported bNumDescriptors 1 bDescriptorType 34 Report wDescriptorLength 59 Report Descriptors: ** UNAVAILABLE ** Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0008 1x 8 bytes bInterval 8 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 1 bAlternateSetting 0 bNumEndpoints 1 bInterfaceClass 3 Human Interface Device bInterfaceSubClass 1 Boot Interface Subclass bInterfaceProtocol 2 Mouse iInterface 0 HID Device Descriptor: bLength 9 bDescriptorType 33 bcdHID 1.11 bCountryCode 0 Not supported bNumDescriptors 1 bDescriptorType 34 Report wDescriptorLength 177 Report Descriptors: ** UNAVAILABLE ** Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x82 EP 2 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0014 1x 20 bytes bInterval 2 can't get device qualifier: Resource temporarily unavailable can't get debug descriptor: Resource temporarily unavailable Device Status: 0x0000 (Bus Powered) On 21 April 2015 at 03:08, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > On Tue, 21 Apr 2015, Tom Yan wrote: > >> Thank you very much for your reply. >> >> So I tried to see if there's any difference between the two devices. I >> can see that the one didn't get enabled by default has an extra >> interface with 0 for the two attributes. But does that matter? Because >> if it does, shouldn't the mouse interface prevents the other one to >> get enabled by default as well? > > No, it doesn't matter. > >> Seems to me the keyboard interface is the first interface for both devices: >> [tom@localhost ~]$ cat >> /sys/devices/pci0000\:00/0000\:00\:14.0/usb3/3-13/3-13\:1.0/bInterfaceSubClass >> 01 >> [tom@localhost ~]$ cat >> /sys/devices/pci0000\:00/0000\:00\:14.0/usb3/3-13/3-13\:1.0/bInterfaceProtocol >> 01 >> [tom@localhost ~]$ cat >> /sys/devices/pci0000\:00/0000\:00\:14.0/usb3/3-14/3-14\:1.0/bInterfaceSubClass >> 01 >> [tom@localhost ~]$ cat >> /sys/devices/pci0000\:00/0000\:00\:14.0/usb3/3-14/3-14\:1.0/bInterfaceProtocol >> 01 >> >> [tom@localhost ~]$ diff <(sudo lsusb -v -s 003:002) <(sudo lsusb -v -s 003:003) >> can't get device qualifier: Resource temporarily unavailable >> can't get debug descriptor: Resource temporarily unavailable >> can't get device qualifier: Resource temporarily unavailable >> can't get debug descriptor: Resource temporarily unavailable > > It's a little difficult to tell what's going on just from the diff. > Can you post the complete lsusb -v output for both devices? > > Alan Stern > -- 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