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

Simplified low level Host demo configuration descriptor parser routines.

1 files changed, 15 insertions, 25 deletions

diff --git a/Demos/Host/LowLevel/KeyboardHostWithParser/ConfigDescriptor.c b/Demos/Host/LowLevel/KeyboardHostWithParser/ConfigDescriptor.c
index bf2c4e051..74817a2f1 100644
--- a/Demos/Host/LowLevel/KeyboardHostWithParser/ConfigDescriptor.c
+++ b/Demos/Host/LowLevel/KeyboardHostWithParser/ConfigDescriptor.c
@@ -51,7 +51,9 @@ uint8_t ProcessConfigurationDescriptor(void)
 	void*    CurrConfigLocation = ConfigDescriptorData;
 	uint16_t CurrConfigBytesRem;
 	
-	USB_Descriptor_Endpoint_t* DataINEndpoint = NULL;
+	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 */
 	switch (USB_Host_GetDeviceConfigDescriptor(1, &CurrConfigBytesRem, ConfigDescriptorData, sizeof(ConfigDescriptorData)))
@@ -65,30 +67,12 @@ uint8_t ProcessConfigurationDescriptor(void)
 		default:
 			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 */
-		if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
+		/* 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_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)
@@ -107,9 +94,9 @@ uint8_t ProcessConfigurationDescriptor(void)
 				return NoCompatibleInterfaceFound;
 			}
 			
-			/* Save the HID report size for later use */
-			HIDReportSize = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_HID_t)->HIDReportLength;			
-
+			/* 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;
 		}
@@ -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;
 }