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Published 20 hours ago • verified publisher icon dlkj

Investigate missing LPM bit

Open dlkj opened this issue 3 years ago • 1 comments

See warning from lsusb -v device descriptor:

  Binary Object Store Descriptor:
  bLength                 5
  bDescriptorType        15
  wTotalLength       0x000c
  bNumDeviceCaps          1
  USB 2.0 Extension Device Capability:
    bLength                 7
    bDescriptorType        16
    bDevCapabilityType      2
    bmAttributes   0x00000000
      (Missing must-be-set LPM bit!)
  USB 2.0 Extension Device Capability:
    bLength                 7
    bDescriptorType        16
    bDevCapabilityType      2
    bmAttributes   0x00000000
      (Missing must-be-set LPM bit!)

May need fixing in https://github.com/mvirkkunen/usb-device

dlkj avatar Jan 08 '22 15:01 dlkj

May be related to https://www.beyondlogic.org/usbnutshell/usb5.shtml#ConfigurationDescriptors - indicates that bit 7 should always be set

dlkj avatar Jan 09 '22 15:01 dlkj