Update keyboard report descriptor for USB compliance (#21626) Running the "HID Tests" suite of the USB 3 Command Verifier (USB3CV) tool resulted in the following error: (HID: 3.2.61) The report descriptor returned in response to a GetDescriptor(Report) must be compliant with the HID specification. Byte Number: 37h ( 55d) Data Field: 91 02 Mnemonic: Output Value: (Variable) Errors: Error: LOGICAL MAX MUST be bounded by Report Size The error stems from the fact that logical minimum and maximum are global items, which means that the next item in a report descriptor inherits the value from the previously set value. In this case the status leds item inherited the logical minimum (=0) and maximum (=255) from the keycodes item. As the status leds set a report size of 1 bit, wich can only hold a boolean, it becomes clear that this range would never fit. The fix is straightforward, we just define a appropriate logical maximum (=1), the mismatch is solved and our keyboard now passes the compliance tests. Defining the logical minimum is redundant in this case but is kept to form a logical block.
2 files changed, 4 insertions(+), 0 deletions(-) M tmk_core/protocol/usb_descriptor.c M tmk_core/protocol/vusb/vusb.c
M tmk_core/protocol/usb_descriptor.c => tmk_core/protocol/usb_descriptor.c +2 -0
@@ 93,6 93,8 @@ const USB_Descriptor_HIDReport_Datatype_t PROGMEM KeyboardReport[] = { HID_RI_USAGE_PAGE(8, 0x08), // LED HID_RI_USAGE_MINIMUM(8, 0x01), // Num Lock HID_RI_USAGE_MAXIMUM(8, 0x05), // Kana HID_RI_LOGICAL_MINIMUM(8, 0x00), HID_RI_LOGICAL_MAXIMUM(8, 0x01), HID_RI_REPORT_COUNT(8, 0x05), HID_RI_REPORT_SIZE(8, 0x01), HID_RI_OUTPUT(8, HID_IOF_DATA | HID_IOF_VARIABLE | HID_IOF_ABSOLUTE | HID_IOF_NON_VOLATILE),
M tmk_core/protocol/vusb/vusb.c => tmk_core/protocol/vusb/vusb.c +2 -0
@@ 435,6 435,8 @@ const PROGMEM uchar keyboard_hid_report[] = { 0x05, 0x08, // Usage Page (LED) 0x19, 0x01, // Usage Minimum (Num Lock) 0x29, 0x05, // Usage Maximum (Kana) 0x15, 0x00, // Logical Minimum (0) 0x25, 0x01, // Logical Maximum (1) 0x95, 0x05, // Report Count (5) 0x75, 0x01, // Report Size (1) 0x91, 0x02, // Output (Data, Variable, Absolute)