Native port driver BSoD

Hardware Arduino Due
29

I am not sure why there is a need for conditional code to send a different Device Descriptor depending on the length of the request.

If I understand the USB specs properly, the device should return the same Device Descriptor, no matter what the length is requested.

The USB code looks like it is trying to handle three scenarios:

  1. CDC only
  2. HID only
  3. Composite: CDC and HID

If the USB code is configured as CDC only, CDC_ENABLED defined and HID_ENABLED not defined, then it should have a Device Descriptor with Device Class of 2.
If the USB code is configured as HID only, CDC_ENABLED not defined and HID_ENABLED defined, then it should have a Device Descriptor with Device Class of 0.
If the USB code is configured as Composite, CDC_ENABLED defined and HID_ENABLED defined, then it should have a Device Descriptor with Device Class of 0.

I believe that you could simplify the code and accomplish this behavior by making the following changes to the code:

  1. Change the preprocessor macro to set Device Class to 0 if HID is defined, this covers the HID only and Composite cases. Otherwise, set Device Class to 2, this covers the CDC only case.
  2. Eliminate the alternate USB_DeviceDescriptor.
  3. Remove the conditional code based on request length.
#ifdef HID_ENABLED
#define DEVICE_CLASS 0x00
#else
#define DEVICE_CLASS 0x02
#endif

//	DEVICE DESCRIPTOR
const DeviceDescriptor USB_DeviceDescriptor =
	D_DEVICE(DEVICE_CLASS,0x00,0x00,64,USB_VID,USB_PID,0x100,IMANUFACTURER,IPRODUCT,0,1);

...

if (USB_DEVICE_DESCRIPTOR_TYPE == t)
	{
		TRACE_CORE(puts("=> USBD_SendDescriptor : USB_DEVICE_DESCRIPTOR_TYPE\r\n");)
		
		desc_addr = (const uint8_t*)&USB_DeviceDescriptor;
                if( *desc_addr > setup.wLength ) {
                    desc_length = setup.wLength;
                }
	}

I haven't fully tested this, but I think this will accomplish what is desired.