HidD_SetOutputReport fail with error 1 (ERROR_INVALID_FUNCTION)

[samchen]

Hi

Below is my usb hid descriptor, and I want to use HidD_SetOutputReport to send data via control transfer.
But it returns fail with error code 1 (ERROR_INVALID_FUNCTION). (OS: Windows 110)
Does anyone have idea how to using control transfer in windows ?
Thanks.
Device Descriptor:
bcdUSB:             0x0200
bDeviceClass:         0x00
bDeviceSubClass:      0x00
bDeviceProtocol:      0x00
bMaxPacketSize0:      0x40 (64)


ConnectionStatus: DeviceConnected
Current Config Value: 0x01
Device Bus Speed:     High
Device Address:       0x37
Open Pipes:              1

Endpoint Descriptor:
bEndpointAddress:     0x81  IN
Transfer Type:   Interrupt
wMaxPacketSize:     0x0040 (64)
bInterval:            0x01

Configuration Descriptor:
wTotalLength:       0x0022
bNumInterfaces:       0x01
bConfigurationValue:  0x01
iConfiguration:       0x00
bmAttributes:         0x80 (Bus Powered )
MaxPower:             0xFA (500 Ma)

Interface Descriptor:
bInterfaceNumber:     0x00
bAlternateSetting:    0x00
bNumEndpoints:        0x01
bInterfaceClass:      0x03 (HID)
bInterfaceSubClass:   0x00
bInterfaceProtocol:   0x00
iInterface:           0x00

HID Descriptor:
bcdHID:             0x0100
bCountryCode:         0x00
bNumDescriptors:      0x01
bDescriptorType:      0x22
wDescriptorLength:  0x003E

Endpoint Descriptor:
bEndpointAddress:     0x81  IN
Transfer Type:   Interrupt
wMaxPacketSize:     0x0040 (64)
bInterval:            0x01

[samchen]

I saw the source code in Generic_Hid_cs_v62 project.
It looks like we can't use HidD_SetOutputReport when there is no output endpoint.
How to set report without out endpoint?
Thanks you
//  Don't attempt to send an Output report if the HID has no Output report.

               if (_myHid.Capabilities.OutputReportByteLength > 0)
               {
                        //  Set the size of the Output report buffer.   

                        var outputReportBuffer = new Byte[_myHid.Capabilities.OutputReportByteLength];

                  //  Store the report ID in the first byte of the buffer:

                  outputReportBuffer[0] = 0x00;

                  //  Store the report data following the report ID.
                  //  Use the data in the combo boxes on the form.

                  outputReportBuffer[1] = Convert.ToByte(CboByte0.SelectedIndex);

                  if (outputReportBuffer.GetUpperBound(0) > 1)
                  {
                     outputReportBuffer[2] = Convert.ToByte(CboByte1.SelectedIndex);
                  }

                  //  Write a report.

                  Boolean success;
                       
                        if (_transferType.Equals(TransferTypes.Control))
                  {
                     {
                        _transferInProgress = true;

                                //  Use a control transfer to send the report,
                                //  even if the HID has an interrupt OUT endpoint.
                                Debug.Print("control transfer");
                        success = _myHid.SendOutputReportViaControlTransfer(_hidHandle, outputReportBuffer);

                        _transferInProgress = false;
                        cmdSendOutputReportControl.Enabled = true;
                     }
                  }

[Jan Axelson]

HidD_SetOutputReport always uses a control transfer.

Compare your code to my Generic_Hid_cs example. Examine the parameters passed to the function.

[samchen]

There are two mistake I made for this issue.
1. USB hid descriptor misses report id for output report.
I have two report id (1 & 2) for input report, but lack of report id for output, so I add report id (3) for output.
When I call HidD_SetOutputReport, the first byte of buffer is 0x03.

2. Buffer size (65)  for output  exceeds maximum packet size (64).
I defines the maximum packet size to 64, and output size to 64, but we need one more byte  for report id (That means the buffer size is 64 + 1).

After fixing these two problem, my program can use HidD_SetOutputReport successfully.

Thanks for your help.
Sam

[Jan Axelson]

Glad you got it working. Thanks for reporting what you found!