Fixed LowLevel JoystickHostWithParser demo not saving the chosen HID interface's report descriptor size.

Simplified low level Host demo configuration descriptor parser routines.

Demos/Host/LowLevel/GenericHIDHost/ConfigDescriptor.c

@@ -51,6 +51,7 @@ uint8_t ProcessConfigurationDescriptor(void)
 	void*    CurrConfigLocation = ConfigDescriptorData;
 	uint16_t CurrConfigBytesRem;
 	
+	USB_Descriptor_Interface_t* HIDInterface    = NULL;
 	USB_Descriptor_Endpoint_t*  DataINEndpoint  = NULL;
 	USB_Descriptor_Endpoint_t*  DataOUTEndpoint = NULL;
 
@@ -67,18 +68,11 @@ uint8_t ProcessConfigurationDescriptor(void)
 			return ControlError;
 	}
 
-	/* Get the first HID interface from the configuration descriptor */
-	if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
-	                              DComp_NextHIDInterface) != DESCRIPTOR_SEARCH_COMP_Found)
-	{
-		/* Descriptor not found, error out */
-		return NoCompatibleInterfaceFound;
-	}
-
 	while (!(DataINEndpoint) || !(DataOUTEndpoint))
 	{
-		/* Get the next HID interface's data endpoint descriptor */
+		/* See if we've found a likely compatible interface, and if there is an endpoint within that interface */
-		if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
+		if (!(HIDInterface) ||
+		    USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
 		                              DComp_NextHIDInterfaceDataEndpoint) != DESCRIPTOR_SEARCH_COMP_Found)
 		{
 			/* Not all HID devices have an OUT endpoint - if we've reached the end of the HID descriptor
@@ -86,9 +80,6 @@ uint8_t ProcessConfigurationDescriptor(void)
 			if (DataINEndpoint)
 			  break;
 			
-			/* Clear any found endpoints */
-			DataOUTEndpoint = NULL;
-
 			/* Get the next HID interface from the configuration descriptor */
 			if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
 										  DComp_NextHIDInterface) != DESCRIPTOR_SEARCH_COMP_Found)
@@ -97,6 +88,12 @@ uint8_t ProcessConfigurationDescriptor(void)
 				return NoCompatibleInterfaceFound;
 			}
 			
+			/* Save the interface in case we need to refer back to it later */
+			HIDInterface = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t);
+
+			/* Clear any found endpoints */
+			DataOUTEndpoint = NULL;
+			
 			/* Skip the remainder of the loop as we have not found an endpoint yet */
 			continue;
 		}

Demos/Host/LowLevel/JoystickHostWithParser/ConfigDescriptor.c

@@ -51,6 +51,8 @@ uint8_t ProcessConfigurationDescriptor(void)
 	void*    CurrConfigLocation = ConfigDescriptorData;
 	uint16_t CurrConfigBytesRem;
 	
+	USB_Descriptor_Interface_t* HIDInterface   = NULL;
+	USB_Descriptor_HID_t*       HIDDescriptor  = NULL;
 	USB_Descriptor_Endpoint_t*  DataINEndpoint = NULL;
 
 	/* Retrieve the entire configuration descriptor into the allocated buffer */
@@ -66,7 +68,14 @@ uint8_t ProcessConfigurationDescriptor(void)
 			return ControlError;
 	}
 
-	/* Get the first HID interface from the configuration descriptor */
+	while (!(DataINEndpoint))
+	{
+		/* See if we've found a likely compatible interface, and if there is an endpoint within that interface */
+		if (!(HIDInterface) ||
+		    USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
+		                              DComp_NextJoystickInterfaceDataEndpoint) != DESCRIPTOR_SEARCH_COMP_Found)
+		{
+			/* Get the next HID interface from the configuration descriptor */
 			if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
 										  DComp_NextJoystickInterface) != DESCRIPTOR_SEARCH_COMP_Found)
 			{
@@ -74,20 +83,20 @@ uint8_t ProcessConfigurationDescriptor(void)
 				return NoCompatibleInterfaceFound;
 			}
 
-	while (!(DataINEndpoint))
+			/* Save the interface in case we need to refer back to it later */
-	{
+			HIDInterface = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t);
-		/* Get the next HID interface's data endpoint descriptor */
+
-		if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
+			/* Get the HID descriptor from the configuration descriptor */
-		                              DComp_NextJoystickInterfaceDataEndpoint) != DESCRIPTOR_SEARCH_COMP_Found)
-		{
-			/* Get the next HID interface from the configuration descriptor */
 			if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
-										  DComp_NextJoystickInterface) != DESCRIPTOR_SEARCH_COMP_Found)
+										  DComp_NextHID) != DESCRIPTOR_SEARCH_COMP_Found)
 			{
 				/* Descriptor not found, error out */
 				return NoCompatibleInterfaceFound;
 			}
 
+			/* Save the HID descriptor for later use */
+			HIDDescriptor = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_HID_t);	
+
 			/* Skip the remainder of the loop as we have not found an endpoint yet */
 			continue;
 		}
@@ -105,6 +114,9 @@ uint8_t ProcessConfigurationDescriptor(void)
 	                   DataINEndpoint->EndpointAddress, DataINEndpoint->EndpointSize, PIPE_BANK_SINGLE);
 	Pipe_SetInterruptPeriod(DataINEndpoint->PollingIntervalMS);
 
+	/* Get the HID report size from the HID report descriptor */
+	HIDReportSize = HIDDescriptor->HIDReportLength;
+
 	/* Valid data found, return success */
 	return SuccessfulConfigRead;
 }

Demos/Host/LowLevel/KeyboardHost/ConfigDescriptor.c

@@ -51,6 +51,7 @@ uint8_t ProcessConfigurationDescriptor(void)
 	void*    CurrConfigLocation = ConfigDescriptorData;
 	uint16_t CurrConfigBytesRem;
 	
+	USB_Descriptor_Interface_t* HIDInterface   = NULL;
 	USB_Descriptor_Endpoint_t*  DataINEndpoint = NULL;
 
 	/* Retrieve the entire configuration descriptor into the allocated buffer */
@@ -66,18 +67,11 @@ uint8_t ProcessConfigurationDescriptor(void)
 			return ControlError;
 	}
 	
-	/* Get the first HID interface from the configuration descriptor */
-	if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
-	                              DComp_NextKeyboardInterface) != DESCRIPTOR_SEARCH_COMP_Found)
-	{
-		/* Descriptor not found, error out */
-		return NoCompatibleInterfaceFound;
-	}
-
 	while (!(DataINEndpoint))
 	{
-		/* Get the next HID interface's data endpoint descriptor */
+		/* See if we've found a likely compatible interface, and if there is an endpoint within that interface */
-		if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
+		if (!(HIDInterface) ||
+		    USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
 		                              DComp_NextKeyboardInterfaceDataEndpoint) != DESCRIPTOR_SEARCH_COMP_Found)
 		{
 			/* Get the next HID interface from the configuration descriptor */
@@ -88,6 +82,9 @@ uint8_t ProcessConfigurationDescriptor(void)
 				return NoCompatibleInterfaceFound;
 			}
 
+			/* Save the interface in case we need to refer back to it later */
+			HIDInterface = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t);
+
 			/* Skip the remainder of the loop as we have not found an endpoint yet */
 			continue;
 		}

Demos/Host/LowLevel/KeyboardHostWithParser/ConfigDescriptor.c

@@ -51,6 +51,8 @@ uint8_t ProcessConfigurationDescriptor(void)
 	void*    CurrConfigLocation = ConfigDescriptorData;
 	uint16_t CurrConfigBytesRem;
 	
+	USB_Descriptor_Interface_t* HIDInterface   = NULL;
+	USB_Descriptor_HID_t*       HIDDescriptor  = NULL;
 	USB_Descriptor_Endpoint_t*  DataINEndpoint = NULL;
 
 	/* Retrieve the entire configuration descriptor into the allocated buffer */
@@ -66,29 +68,11 @@ uint8_t ProcessConfigurationDescriptor(void)
 			return ControlError;
 	}
 
-	/* Get the first HID interface from the configuration descriptor */
-	if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
-	                              DComp_NextKeyboardInterface) != DESCRIPTOR_SEARCH_COMP_Found)
-	{
-		/* Descriptor not found, error out */
-		return NoCompatibleInterfaceFound;
-	}
-
-	/* Get the HID descriptor from the configuration descriptor */
-	if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
-	                              DComp_NextHID) != DESCRIPTOR_SEARCH_COMP_Found)
-	{
-		/* Descriptor not found, error out */
-		return NoCompatibleInterfaceFound;
-	}
-	
-	/* Save the HID report size for later use */
-	HIDReportSize = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_HID_t)->HIDReportLength;
-
 	while (!(DataINEndpoint))
 	{
-		/* Get the next HID interface's data endpoint descriptor */
+		/* See if we've found a likely compatible interface, and if there is an endpoint within that interface */
-		if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
+		if (!(HIDInterface) ||
+		    USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
 		                              DComp_NextKeyboardInterfaceDataEndpoint) != DESCRIPTOR_SEARCH_COMP_Found)
 		{
 			/* Get the next HID interface from the configuration descriptor */
@@ -99,6 +83,9 @@ uint8_t ProcessConfigurationDescriptor(void)
 				return NoCompatibleInterfaceFound;
 			}
 			
+			/* Save the interface in case we need to refer back to it later */
+			HIDInterface = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t);
+
 			/* Get the HID descriptor from the configuration descriptor */
 			if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
 										  DComp_NextHID) != DESCRIPTOR_SEARCH_COMP_Found)
@@ -107,8 +94,8 @@ uint8_t ProcessConfigurationDescriptor(void)
 				return NoCompatibleInterfaceFound;
 			}
 			
-			/* Save the HID report size for later use */
+			/* Save the HID descriptor for later use */
-			HIDReportSize = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_HID_t)->HIDReportLength;			
+			HIDDescriptor = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_HID_t);	
 			
 			/* Skip the remainder of the loop as we have not found an endpoint yet */
 			continue;
@@ -127,6 +114,9 @@ uint8_t ProcessConfigurationDescriptor(void)
 	                   DataINEndpoint->EndpointAddress, DataINEndpoint->EndpointSize, PIPE_BANK_SINGLE);
 	Pipe_SetInterruptPeriod(DataINEndpoint->PollingIntervalMS);
 
+	/* Get the HID report size from the HID report descriptor */
+	HIDReportSize = HIDDescriptor->HIDReportLength;
+
 	/* Valid data found, return success */
 	return SuccessfulConfigRead;
 }

Demos/Host/LowLevel/MIDIHost/ConfigDescriptor.c

@@ -51,6 +51,7 @@ uint8_t ProcessConfigurationDescriptor(void)
 	void*    CurrConfigLocation = ConfigDescriptorData;
 	uint16_t CurrConfigBytesRem;
 	
+	USB_Descriptor_Interface_t* MIDIInterface   = NULL;
 	USB_Descriptor_Endpoint_t*  DataINEndpoint  = NULL;
 	USB_Descriptor_Endpoint_t*  DataOUTEndpoint = NULL;
 
@@ -67,24 +68,13 @@ uint8_t ProcessConfigurationDescriptor(void)
 			return ControlError;
 	}
 	
-	/* Get the first MIDI interface from the configuration descriptor */
-	if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
-	                              DComp_NextMIDIStreamingInterface) != DESCRIPTOR_SEARCH_COMP_Found)
-	{
-		/* Descriptor not found, error out */
-		return NoCompatibleInterfaceFound;
-	}
-
 	while (!(DataINEndpoint) || !(DataOUTEndpoint))
 	{
-		/* Get the next MIDI interface's data endpoint descriptor */
+		/* See if we've found a likely compatible interface, and if there is an endpoint within that interface */
-		if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
+		if (!(MIDIInterface) ||
+		    USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
 		                              DComp_NextMIDIStreamingDataEndpoint) != DESCRIPTOR_SEARCH_COMP_Found)
 		{
-			/* Clear any found endpoints */
-			DataINEndpoint  = NULL;
-			DataOUTEndpoint = NULL;
-
 			/* Get the next Mass Storage interface from the configuration descriptor */
 			if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
 										  DComp_NextMIDIStreamingInterface) != DESCRIPTOR_SEARCH_COMP_Found)
@@ -93,6 +83,13 @@ uint8_t ProcessConfigurationDescriptor(void)
 				return NoCompatibleInterfaceFound;
 			}
 
+			/* Save the interface in case we need to refer back to it later */
+			MIDIInterface = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t);
+
+			/* Clear any found endpoints */
+			DataINEndpoint  = NULL;
+			DataOUTEndpoint = NULL;
+
 			/* Skip the remainder of the loop as we have not found an endpoint yet */
 			continue;
 		}

Demos/Host/LowLevel/MassStorageHost/ConfigDescriptor.c

@@ -51,6 +51,7 @@ uint8_t ProcessConfigurationDescriptor(void)
 	void*    CurrConfigLocation = ConfigDescriptorData;
 	uint16_t CurrConfigBytesRem;
 	
+	USB_Descriptor_Interface_t* MSInterface     = NULL;
 	USB_Descriptor_Endpoint_t*  DataINEndpoint  = NULL;
 	USB_Descriptor_Endpoint_t*  DataOUTEndpoint = NULL;
 
@@ -67,24 +68,13 @@ uint8_t ProcessConfigurationDescriptor(void)
 			return ControlError;
 	}
 
-	/* Get the first Mass Storage interface from the configuration descriptor */
-	if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
-	                              DComp_NextMSInterface) != DESCRIPTOR_SEARCH_COMP_Found)
-	{
-		/* Descriptor not found, error out */
-		return NoCompatibleInterfaceFound;
-	}
-
 	while (!(DataINEndpoint) || !(DataOUTEndpoint))
 	{
-		/* Get the next Mass Storage interface's data endpoint descriptor */
+		/* See if we've found a likely compatible interface, and if there is an endpoint within that interface */
-		if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
+		if (!(MSInterface) ||
+		    USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
 		                              DComp_NextMSInterfaceBulkDataEndpoint) != DESCRIPTOR_SEARCH_COMP_Found)
 		{
-			/* Clear any found endpoints */
-			DataINEndpoint  = NULL;
-			DataOUTEndpoint = NULL;
-
 			/* Get the next Mass Storage interface from the configuration descriptor */
 			if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
 										  DComp_NextMSInterface) != DESCRIPTOR_SEARCH_COMP_Found)
@@ -93,6 +83,13 @@ uint8_t ProcessConfigurationDescriptor(void)
 				return NoCompatibleInterfaceFound;
 			}
 
+			/* Save the interface in case we need to refer back to it later */
+			MSInterface = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t);
+
+			/* Clear any found endpoints */
+			DataINEndpoint  = NULL;
+			DataOUTEndpoint = NULL;
+
 			/* Skip the remainder of the loop as we have not found an endpoint yet */
 			continue;
 		}

Demos/Host/LowLevel/MouseHost/ConfigDescriptor.c

@@ -51,6 +51,7 @@ uint8_t ProcessConfigurationDescriptor(void)
 	void*    CurrConfigLocation = ConfigDescriptorData;
 	uint16_t CurrConfigBytesRem;
 	
+	USB_Descriptor_Interface_t* HIDInterface   = NULL;
 	USB_Descriptor_Endpoint_t*  DataINEndpoint = NULL;
 
 	/* Retrieve the entire configuration descriptor into the allocated buffer */
@@ -66,18 +67,11 @@ uint8_t ProcessConfigurationDescriptor(void)
 			return ControlError;
 	}
 
-	/* Get the first HID interface from the configuration descriptor */
-	if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
-	                              DComp_NextMouseInterface) != DESCRIPTOR_SEARCH_COMP_Found)
-	{
-		/* Descriptor not found, error out */
-		return NoCompatibleInterfaceFound;
-	}
-
 	while (!(DataINEndpoint))
 	{
-		/* Get the next HID interface's data endpoint descriptor */
+		/* See if we've found a likely compatible interface, and if there is an endpoint within that interface */
-		if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
+		if (!(HIDInterface) ||
+		    USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
 		                              DComp_NextMouseInterfaceDataEndpoint) != DESCRIPTOR_SEARCH_COMP_Found)
 		{
 			/* Get the next HID interface from the configuration descriptor */
@@ -88,6 +82,9 @@ uint8_t ProcessConfigurationDescriptor(void)
 				return NoCompatibleInterfaceFound;
 			}
 
+			/* Save the interface in case we need to refer back to it later */
+			HIDInterface = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t);
+
 			/* Skip the remainder of the loop as we have not found an endpoint yet */
 			continue;
 		}

Demos/Host/LowLevel/MouseHostWithParser/ConfigDescriptor.c

@@ -51,6 +51,8 @@ uint8_t ProcessConfigurationDescriptor(void)
 	void*    CurrConfigLocation = ConfigDescriptorData;
 	uint16_t CurrConfigBytesRem;
 	
+	USB_Descriptor_Interface_t* HIDInterface   = NULL;
+	USB_Descriptor_HID_t*       HIDDescriptor  = NULL;
 	USB_Descriptor_Endpoint_t*  DataINEndpoint = NULL;
 
 	/* Retrieve the entire configuration descriptor into the allocated buffer */
@@ -66,29 +68,11 @@ uint8_t ProcessConfigurationDescriptor(void)
 			return ControlError;
 	}
 	
-	/* Get the first HID interface from the configuration descriptor */
-	if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
-	                              DComp_NextMouseInterface) != DESCRIPTOR_SEARCH_COMP_Found)
-	{
-		/* Descriptor not found, error out */
-		return NoCompatibleInterfaceFound;
-	}
-
-	/* Get the HID descriptor from the configuration descriptor */
-	if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
-	                              DComp_NextHID) != DESCRIPTOR_SEARCH_COMP_Found)
-	{
-		/* Descriptor not found, error out */
-		return NoCompatibleInterfaceFound;
-	}
-	
-	/* Save the HID report size for later use */
-	HIDReportSize = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_HID_t)->HIDReportLength;
-
 	while (!(DataINEndpoint))
 	{
-		/* Get the next HID interface's data endpoint descriptor */
+		/* See if we've found a likely compatible interface, and if there is an endpoint within that interface */
-		if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
+		if (!(HIDInterface) ||
+		    USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
 		                              DComp_NextMouseInterfaceDataEndpoint) != DESCRIPTOR_SEARCH_COMP_Found)
 		{
 			/* Get the next HID interface from the configuration descriptor */
@@ -99,6 +83,9 @@ uint8_t ProcessConfigurationDescriptor(void)
 				return NoCompatibleInterfaceFound;
 			}
 			
+			/* Save the interface in case we need to refer back to it later */
+			HIDInterface = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t);
+
 			/* Get the HID descriptor from the configuration descriptor */
 			if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
 										  DComp_NextHID) != DESCRIPTOR_SEARCH_COMP_Found)
@@ -107,8 +94,8 @@ uint8_t ProcessConfigurationDescriptor(void)
 				return NoCompatibleInterfaceFound;
 			}
 			
-			/* Save the HID report size for later use */
+			/* Save the HID descriptor for later use */
-			HIDReportSize = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_HID_t)->HIDReportLength;			
+			HIDDescriptor = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_HID_t);	
 			
 			/* Skip the remainder of the loop as we have not found an endpoint yet */
 			continue;
@@ -127,6 +114,9 @@ uint8_t ProcessConfigurationDescriptor(void)
 	                   DataINEndpoint->EndpointAddress, DataINEndpoint->EndpointSize, PIPE_BANK_SINGLE);
 	Pipe_SetInterruptPeriod(DataINEndpoint->PollingIntervalMS);
 
+	/* Get the HID report size from the HID report descriptor */
+	HIDReportSize = HIDDescriptor->HIDReportLength;
+
 	/* Valid data found, return success */
 	return SuccessfulConfigRead;
 }

Demos/Host/LowLevel/PrinterHost/ConfigDescriptor.c

@@ -50,6 +50,7 @@ uint8_t ProcessConfigurationDescriptor(void)
 	void*    CurrConfigLocation = ConfigDescriptorData;
 	uint16_t CurrConfigBytesRem;
 	
+	USB_Descriptor_Interface_t* PrinterInterface = NULL;
 	USB_Descriptor_Endpoint_t*  DataINEndpoint   = NULL;
 	USB_Descriptor_Endpoint_t*  DataOUTEndpoint  = NULL;
 
@@ -66,28 +67,13 @@ uint8_t ProcessConfigurationDescriptor(void)
 			return ControlError;
 	}
 	
-	/* Get the first Printer interface from the configuration descriptor */
-	if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
-	                              DComp_NextBidirectionalPrinterInterface) != DESCRIPTOR_SEARCH_COMP_Found)
-	{
-		/* Descriptor not found, error out */
-		return NoCompatibleInterfaceFound;
-	}
-
-	/* Save Printer interface details for later use */
-	PrinterInterfaceNumber = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t)->InterfaceNumber;
-	PrinterAltSetting      = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t)->AlternateSetting;
-
 	while (!(DataINEndpoint) || !(DataOUTEndpoint))
 	{
-		/* Get the next Printer interface's data endpoint descriptor */
+		/* See if we've found a likely compatible interface, and if there is an endpoint within that interface */
-		if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
+		if (!(PrinterInterface) ||
+		    USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
 		                              DComp_NextPrinterInterfaceBulkDataEndpoint) != DESCRIPTOR_SEARCH_COMP_Found)
 		{
-			/* Clear any found endpoints */
-			DataINEndpoint  = NULL;
-			DataOUTEndpoint = NULL;
-
 			/* Get the next Printer interface from the configuration descriptor */
 			if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
 										  DComp_NextBidirectionalPrinterInterface) != DESCRIPTOR_SEARCH_COMP_Found)
@@ -96,9 +82,12 @@ uint8_t ProcessConfigurationDescriptor(void)
 				return NoCompatibleInterfaceFound;
 			}
 			
-			/* Save Printer interface details for later use */
+			/* Save the interface in case we need to refer back to it later */
-			PrinterInterfaceNumber = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t)->InterfaceNumber;
+			PrinterInterface = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t);
-			PrinterAltSetting      = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t)->AlternateSetting;			
+
+			/* Clear any found endpoints */
+			DataINEndpoint  = NULL;
+			DataOUTEndpoint = NULL;
 
 			/* Skip the remainder of the loop as we have not found an endpoint yet */
 			continue;
@@ -114,6 +103,10 @@ uint8_t ProcessConfigurationDescriptor(void)
 		  DataOUTEndpoint = EndpointData;
 	}
 	
+	/* Save Printer interface details for later use */
+	PrinterInterfaceNumber = PrinterInterface->InterfaceNumber;
+	PrinterAltSetting      = PrinterInterface->AlternateSetting;			
+
 	/* Configure the Printer data IN pipe */
 	Pipe_ConfigurePipe(PRINTER_DATA_IN_PIPE, EP_TYPE_BULK, PIPE_TOKEN_IN,
 	                   DataINEndpoint->EndpointAddress, DataINEndpoint->EndpointSize, PIPE_BANK_SINGLE);

Demos/Host/LowLevel/RNDISEthernetHost/ConfigDescriptor.c

@@ -51,6 +51,7 @@ uint8_t ProcessConfigurationDescriptor(void)
 	void*    CurrConfigLocation = ConfigDescriptorData;
 	uint16_t CurrConfigBytesRem;
 	
+	USB_Descriptor_Interface_t* RNDISControlInterface  = NULL;
 	USB_Descriptor_Endpoint_t*  DataINEndpoint         = NULL;
 	USB_Descriptor_Endpoint_t*  DataOUTEndpoint        = NULL;
 	USB_Descriptor_Endpoint_t*  NotificationEndpoint   = NULL;
@@ -68,18 +69,11 @@ uint8_t ProcessConfigurationDescriptor(void)
 			return ControlError;
 	}
 
-	/* Get the first RNDIS control interface from the configuration descriptor */
-	if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
-	                              DComp_NextCDCControlInterface) != DESCRIPTOR_SEARCH_COMP_Found)
-	{
-		/* Descriptor not found, error out */
-		return NoCompatibleInterfaceFound;
-	}
-
 	while (!(DataINEndpoint) || !(DataOUTEndpoint) || !(NotificationEndpoint))
 	{
-		/* Get the next RNDIS interface's endpoint descriptor */
+		/* See if we've found a likely compatible interface, and if there is an endpoint within that interface */
-		if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
+		if (!(RNDISControlInterface) ||
+		    USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
 		                              DComp_NextCDCDataInterfaceEndpoint) != DESCRIPTOR_SEARCH_COMP_Found)
 		{
 			/* Check if we have already found the control interface's notification endpoint or not */
@@ -107,6 +101,9 @@ uint8_t ProcessConfigurationDescriptor(void)
 					return NoCompatibleInterfaceFound;
 				}
 
+				/* Save the interface in case we need to refer back to it later */
+				RNDISControlInterface = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t);
+
 				/* Clear any found endpoints */
 				NotificationEndpoint = NULL;
 			}

Demos/Host/LowLevel/StillImageHost/ConfigDescriptor.c

@@ -51,6 +51,7 @@ uint8_t ProcessConfigurationDescriptor(void)
 	void*    CurrConfigLocation = ConfigDescriptorData;
 	uint16_t CurrConfigBytesRem;
 	
+	USB_Descriptor_Interface_t* StillImageInterface = NULL;
 	USB_Descriptor_Endpoint_t*  DataINEndpoint      = NULL;
 	USB_Descriptor_Endpoint_t*  DataOUTEndpoint     = NULL;
 	USB_Descriptor_Endpoint_t*  EventsEndpoint      = NULL;
@@ -68,25 +69,13 @@ uint8_t ProcessConfigurationDescriptor(void)
 			return ControlError;
 	}
 
-	/* Get the first Still Image interface from the configuration descriptor */
-	if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
-	                              DComp_NextStillImageInterface) != DESCRIPTOR_SEARCH_COMP_Found)
-	{
-		/* Descriptor not found, error out */
-		return NoCompatibleInterfaceFound;
-	}
-
 	while (!(DataINEndpoint) || !(DataOUTEndpoint))
 	{
-		/* Get the next Still Image interface's data endpoint descriptor */
+		/* See if we've found a likely compatible interface, and if there is an endpoint within that interface */
-		if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
+		if (!(StillImageInterface) ||
+		    USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
 		                              DComp_NextStillImageInterfaceDataEndpoint) != DESCRIPTOR_SEARCH_COMP_Found)
 		{
-			/* Clear any found endpoints */
-			DataINEndpoint  = NULL;
-			DataOUTEndpoint = NULL;
-			EventsEndpoint  = NULL;
-
 			/* Get the next Still Image interface from the configuration descriptor */
 			if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
 										  DComp_NextStillImageInterface) != DESCRIPTOR_SEARCH_COMP_Found)
@@ -95,6 +84,14 @@ uint8_t ProcessConfigurationDescriptor(void)
 				return NoCompatibleInterfaceFound;
 			}
 
+			/* Save the interface in case we need to refer back to it later */
+			StillImageInterface = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t);
+
+			/* Clear any found endpoints */
+			DataINEndpoint  = NULL;
+			DataOUTEndpoint = NULL;
+			EventsEndpoint  = NULL;
+
 			/* Skip the remainder of the loop as we have not found an endpoint yet */
 			continue;
 		}

Demos/Host/LowLevel/VirtualSerialHost/ConfigDescriptor.c

@@ -51,6 +51,7 @@ uint8_t ProcessConfigurationDescriptor(void)
 	void*    CurrConfigLocation = ConfigDescriptorData;
 	uint16_t CurrConfigBytesRem;
 	
+	USB_Descriptor_Interface_t* CDCControlInterface  = NULL;
 	USB_Descriptor_Endpoint_t*  DataINEndpoint       = NULL;
 	USB_Descriptor_Endpoint_t*  DataOUTEndpoint      = NULL;
 	USB_Descriptor_Endpoint_t*  NotificationEndpoint = NULL;
@@ -68,18 +69,11 @@ uint8_t ProcessConfigurationDescriptor(void)
 			return ControlError;
 	}
 
-	/* Get the first CDC control interface from the configuration descriptor */
-	if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
-	                              DComp_NextCDCControlInterface) != DESCRIPTOR_SEARCH_COMP_Found)
-	{
-		/* Descriptor not found, error out */
-		return NoCompatibleInterfaceFound;
-	}
-
 	while (!(DataINEndpoint) || !(DataOUTEndpoint) || !(NotificationEndpoint))
 	{
-		/* Get the next CDC interface's endpoint descriptor */
+		/* See if we've found a likely compatible interface, and if there is an endpoint within that interface */
-		if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
+		if (!(CDCControlInterface) ||
+		    USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
 		                              DComp_NextCDCDataInterfaceEndpoint) != DESCRIPTOR_SEARCH_COMP_Found)
 		{
 			/* Check if we have already found the control interface's notification endpoint or not */
@@ -107,6 +101,9 @@ uint8_t ProcessConfigurationDescriptor(void)
 					return NoCompatibleInterfaceFound;
 				}
 
+				/* Save the interface in case we need to refer back to it later */
+				CDCControlInterface = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t);
+
 				/* Clear any found endpoints */
 				NotificationEndpoint = NULL;
 			}

Projects/MissileLauncher/ConfigDescriptor.c

@@ -51,6 +51,7 @@ uint8_t ProcessConfigurationDescriptor(void)
 	void*    CurrConfigLocation = ConfigDescriptorData;
 	uint16_t CurrConfigBytesRem;
 	
+	USB_Descriptor_Interface_t* HIDInterface    = NULL;
 	USB_Descriptor_Endpoint_t*  DataINEndpoint  = NULL;
 	USB_Descriptor_Endpoint_t*  DataOUTEndpoint = NULL;
 
@@ -67,18 +68,11 @@ uint8_t ProcessConfigurationDescriptor(void)
 			return ControlError;
 	}
 
-	/* Get the first HID interface from the configuration descriptor */
-	if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
-	                              DComp_NextHIDInterface) != DESCRIPTOR_SEARCH_COMP_Found)
-	{
-		/* Descriptor not found, error out */
-		return NoCompatibleInterfaceFound;
-	}
-
 	while (!(DataINEndpoint) || !(DataOUTEndpoint))
 	{
-		/* Get the next HID interface's data endpoint descriptor */
+		/* See if we've found a likely compatible interface, and if there is an endpoint within that interface */
-		if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
+		if (!(HIDInterface) ||
+		    USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
 		                              DComp_NextHIDInterfaceDataEndpoint) != DESCRIPTOR_SEARCH_COMP_Found)
 		{
 			/* Not all HID devices have an OUT endpoint - if we've reached the end of the HID descriptor
@@ -86,9 +80,6 @@ uint8_t ProcessConfigurationDescriptor(void)
 			if (DataINEndpoint)
 			  break;
 			
-			/* Clear any found endpoints */
-			DataOUTEndpoint = NULL;
-
 			/* Get the next HID interface from the configuration descriptor */
 			if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
 										  DComp_NextHIDInterface) != DESCRIPTOR_SEARCH_COMP_Found)
@@ -97,6 +88,12 @@ uint8_t ProcessConfigurationDescriptor(void)
 				return NoCompatibleInterfaceFound;
 			}
 			
+			/* Save the interface in case we need to refer back to it later */
+			HIDInterface = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t);
+
+			/* Clear any found endpoints */
+			DataOUTEndpoint = NULL;
+
 			/* Skip the remainder of the loop as we have not found an endpoint yet */
 			continue;
 		}