Once upon a time, I used to be able to dump the USB report descriptors of my input devices after unlinking them, but for some reason, not anymore.root@spark ~ # dmesg|tail[239486.804224] logitech-hidpp-device 0003:046D:404D.02B3: input,hidraw5: USB HID v1.11 Keyboard [Logitech K400 Plus] on usb-0000:00:14.0-10.3:1[239535.214726] usb 2-10.3: USB disconnect, device number 115[239538.010455] usb 2-10.3: new full-speed USB device number 116 using xhci_hcd[239538.125768] usb 2-10.3: New USB device found, idVendor=046d, idProduct=c52b[239538.125770] usb 2-10.3: New USB device strings: Mfr=1, Product=2, SerialNumber=0[239538.125771] usb 2-10.3: Product: USB Receiver[239538.125772] usb 2-10.3: Manufacturer: Logitech[239538.135925] logitech-djreceiver 0003:046D:C52B.02B6: hiddev0,hidraw4: USB HID v1.11 Device [Logitech USB Receiver] on usb-0000:00:14.0-10.3/input2[239538.264789] input: Logitech K400 Plus as /devices/pci0000:00/0000:00:14.0/usb2/2-10/2-10.3/2-10.3:1.2/0003:046D:C52B.02B6/0003:046D:404D.02B7/input/input340[239538.264987] logitech-hidpp-device 0003:046D:404D.02B7: input,hidraw5: USB HID v1.11 Keyboard [Logitech K400 Plus] on usb-0000:00:14.0-10.3:1root@spark ~ # echo -n 2-10.3 > /sys/bus/usb/drivers/usb/unbindroot@spark ~ # lsusb -vd 046d:c52bBus 002 Device 116: ID 046d:c52b Logitech, Inc. Unifying ReceiverDevice Descriptor:  bLength                18  bDescriptorType         1  bcdUSB               2.00  bDeviceClass            0 (Defined at Interface level)  bDeviceSubClass         0   bDeviceProtocol         0   bMaxPacketSize0        32  idVendor           0x046d Logitech, Inc.  idProduct          0xc52b Unifying Receiver  bcdDevice           24.01  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 RQR24.01_B0023    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 No Subclass      bInterfaceProtocol      0 None      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               2Device Status:     0x0000  (Bus Powered)The report descriptors should show up in place of the ** UNAVAILABLE ** texts.These steps worked well about 2 years ago, but not anymore. Am I missing something?
Cannot dump USB report descriptors, not even after unbinding the device
usb;dump