Changed the parameters and behaviour of the USB_GetDeviceConfigDescriptor() function so that it now performs size checks and data validations internally, to simplify user code.

1 files changed, 16 insertions, 23 deletions

diff --git a/Demos/Host/LowLevel/PrinterHost/ConfigDescriptor.c b/Demos/Host/LowLevel/PrinterHost/ConfigDescriptor.c
index d4eaff94a..22d84c5aa 100644
--- a/Demos/Host/LowLevel/PrinterHost/ConfigDescriptor.c
+++ b/Demos/Host/LowLevel/PrinterHost/ConfigDescriptor.c
@@ -36,32 +36,26 @@ uint8_t PrinterAltSetting;
 

 uint8_t ProcessConfigurationDescriptor(void)

 {

-	uint8_t* ConfigDescriptorData;

-	uint16_t ConfigDescriptorSize;

-	uint8_t  ErrorCode;

+	uint8_t  ConfigDescriptorData[512];

+	uint8_t* CurrConfigLocation = ConfigDescriptorData;

+	uint16_t CurrConfigBytesRem;

 	uint8_t  FoundEndpoints = 0;

-	

-	/* Get Configuration Descriptor size from the device */

-	if (USB_GetDeviceConfigDescriptor(1, &ConfigDescriptorSize, NULL) != HOST_SENDCONTROL_Successful)

-	  return ControlError;

-	

-	/* Ensure that the Configuration Descriptor isn't too large */

-	if (ConfigDescriptorSize > MAX_CONFIG_DESCRIPTOR_SIZE)

-	  return DescriptorTooLarge;

-	  

-	/* Allocate enough memory for the entire config descriptor */

-	ConfigDescriptorData = alloca(ConfigDescriptorSize);

 

 	/* Retrieve the entire configuration descriptor into the allocated buffer */

-	USB_GetDeviceConfigDescriptor(1, &ConfigDescriptorSize, ConfigDescriptorData);

-	

-	/* Validate returned data - ensure first entry is a configuration header descriptor */

-	if (DESCRIPTOR_TYPE(ConfigDescriptorData) != DTYPE_Configuration)

-	  return InvalidConfigDataReturned;

+	switch (USB_GetDeviceConfigDescriptor(1, &CurrConfigBytesRem, ConfigDescriptorData, sizeof(ConfigDescriptorData)))

+	{

+		case HOST_GETCONFIG_Successful:

+			break;

+		case HOST_GETCONFIG_InvalidData:

+			return InvalidConfigDataReturned;

+		case HOST_GETCONFIG_BuffOverflow:

+			return DescriptorTooLarge;

+		default:

+			return ControlError;

+	}

 	

 	/* Get the printer interface from the configuration descriptor */

-	if ((ErrorCode = USB_GetNextDescriptorComp(&ConfigDescriptorSize, &ConfigDescriptorData,

-	                                           DComp_NextBidirectionalPrinterInterface)))

+	if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation, DComp_NextBidirectionalPrinterInterface))

 	{

 		/* Descriptor not found, error out */

 		return NoInterfaceFound;

@@ -74,8 +68,7 @@ uint8_t ProcessConfigurationDescriptor(void)
 	while (FoundEndpoints != ((1 << PRINTER_DATA_OUT_PIPE) | (1 << PRINTER_DATA_IN_PIPE)))

 	{

 		/* Fetch the next bulk endpoint from the current printer interface */

-		if ((ErrorCode = USB_GetNextDescriptorComp(&ConfigDescriptorSize, &ConfigDescriptorData,

-		                                           DComp_NextInterfaceBulkDataEndpoint)))

+		if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation, DComp_NextInterfaceBulkDataEndpoint))

 		{

 			/* Descriptor not found, error out */

 			return NoEndpointFound;