Added new USB_DeviceState variable to keep track of the current Device mode USB state.

Added new Endpoint_ClearStatusStage() convenience function to assist with the status stages of control transfers.

Removed vague USB_IsConnected global - test USB_DeviceState or USB_HostState explicitly to gain previous functionality.

Removed USB_IsSuspended global - test USB_DeviceState against DEVICE_STATE_Suspended instead.

Fixed possible enumeration errors from spinloops which may fail to exit if the USB connection is severed before the exit condition becomes true.

3 files changed, 81 insertions, 51 deletions

diff --git a/Bootloaders/CDC/BootloaderCDC.c b/Bootloaders/CDC/BootloaderCDC.c
index d875b842d..cbcfd7e6c 100644
--- a/Bootloaders/CDC/BootloaderCDC.c
+++ b/Bootloaders/CDC/BootloaderCDC.c
@@ -165,9 +165,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 				

 				Endpoint_ClearIN();

 				

-				/* Acknowledge status stage */

-				while (!(Endpoint_IsOUTReceived()));

-				Endpoint_ClearOUT();

+				Endpoint_ClearStatusStage();

 			}

 			

 			break;

@@ -176,16 +174,18 @@ void EVENT_USB_UnhandledControlPacket(void)
 			{

 				Endpoint_ClearSETUP();

 

-				while (!(Endpoint_IsOUTReceived()));

-

+				while (!(Endpoint_IsOUTReceived()))

+				{				

+					if (USB_DeviceState == DEVICE_STATE_Unattached)

+					  return;

+				}

+			

 				for (uint8_t i = 0; i < sizeof(LineCoding); i++)

 				  *(LineCodingData++) = Endpoint_Read_Byte();

 

 				Endpoint_ClearOUT();

 

-				/* Acknowledge status stage */

-				while (!(Endpoint_IsINReady()));

-				Endpoint_ClearIN();

+				Endpoint_ClearStatusStage();

 			}

 	

 			break;

@@ -194,9 +194,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 			{

 				Endpoint_ClearSETUP();

 				

-				/* Acknowledge status stage */

-				while (!(Endpoint_IsINReady()));

-				Endpoint_ClearIN();

+				Endpoint_ClearStatusStage();

 			}

 	

 			break;

@@ -333,7 +331,12 @@ static uint8_t FetchNextCommandByte(void)
 	while (!(Endpoint_IsReadWriteAllowed()))

 	{

 		Endpoint_ClearOUT();

-		while (!(Endpoint_IsOUTReceived()));

+

+		while (!(Endpoint_IsOUTReceived()))

+		{

+			if (USB_DeviceState == DEVICE_STATE_Unattached)

+			  return 0;

+		}

 	}

 	

 	/* Fetch the next byte from the OUT endpoint */

@@ -354,7 +357,12 @@ static void WriteNextResponseByte(const uint8_t Response)
 	if (!(Endpoint_IsReadWriteAllowed()))

 	{

 		Endpoint_ClearIN();

-		while (!(Endpoint_IsINReady()));

+		

+		while (!(Endpoint_IsINReady()))

+		{				

+			if (USB_DeviceState == DEVICE_STATE_Unattached)

+			  return;

+		}

 	}

 	

 	/* Write the next byte to the OUT endpoint */

@@ -563,12 +571,21 @@ void CDC_Task(void)
 		/* If a full endpoint's worth of data was sent, we need to send an empty packet afterwards to signal end of transfer */

 		if (IsEndpointFull)

 		{

-			while (!(Endpoint_IsINReady()));

+			while (!(Endpoint_IsINReady()))

+			{				

+				if (USB_DeviceState == DEVICE_STATE_Unattached)

+				  return;

+			}

+

 			Endpoint_ClearIN();

 		}

 

 		/* Wait until the data has been sent to the host */

-		while (!(Endpoint_IsINReady()));

+		while (!(Endpoint_IsINReady()))

+		{				

+			if (USB_DeviceState == DEVICE_STATE_Unattached)

+			  return;

+		}

 		

 		/* Select the OUT endpoint */

 		Endpoint_SelectEndpoint(CDC_RX_EPNUM);

diff --git a/Bootloaders/DFU/BootloaderDFU.c b/Bootloaders/DFU/BootloaderDFU.c
index 2086a91d2..f9c8195f3 100644
--- a/Bootloaders/DFU/BootloaderDFU.c
+++ b/Bootloaders/DFU/BootloaderDFU.c
@@ -177,7 +177,11 @@ void EVENT_USB_UnhandledControlPacket(void)
 			/* If the request has a data stage, load it into the command struct */

 			if (SentCommand.DataSize)

 			{

-				while (!(Endpoint_IsOUTReceived()));

+				while (!(Endpoint_IsOUTReceived()))

+				{				

+					if (USB_DeviceState == DEVICE_STATE_Unattached)

+					  return;

+				}

 

 				/* First byte of the data stage is the DNLOAD request's command */

 				SentCommand.Command = Endpoint_Read_Byte();

@@ -235,7 +239,12 @@ void EVENT_USB_UnhandledControlPacket(void)
 							if (!(Endpoint_BytesInEndpoint()))

 							{

 								Endpoint_ClearOUT();

-								while (!(Endpoint_IsOUTReceived()));

+

+								while (!(Endpoint_IsOUTReceived()))

+								{				

+									if (USB_DeviceState == DEVICE_STATE_Unattached)

+									  return;

+								}

 							}

 

 							/* Write the next word into the current flash page */

@@ -279,7 +288,12 @@ void EVENT_USB_UnhandledControlPacket(void)
 							if (!(Endpoint_BytesInEndpoint()))

 							{

 								Endpoint_ClearOUT();

-								while (!(Endpoint_IsOUTReceived()));

+

+								while (!(Endpoint_IsOUTReceived()))

+								{				

+									if (USB_DeviceState == DEVICE_STATE_Unattached)

+									  return;

+								}

 							}

 

 							/* Read the byte from the USB interface and write to to the EEPROM */

@@ -297,16 +311,18 @@ void EVENT_USB_UnhandledControlPacket(void)
 

 			Endpoint_ClearOUT();

 

-			/* Acknowledge status stage */

-			while (!(Endpoint_IsINReady()));

-			Endpoint_ClearIN();

-				

+			Endpoint_ClearStatusStage();

+

 			break;

 		case DFU_UPLOAD:

 			Endpoint_ClearSETUP();

 

-			while (!(Endpoint_IsINReady()));

-

+			while (!(Endpoint_IsINReady()))

+			{				

+				if (USB_DeviceState == DEVICE_STATE_Unattached)

+				  return;

+			}

+							

 			if (DFU_State != dfuUPLOAD_IDLE)

 			{

 				if ((DFU_State == dfuERROR) && IS_ONEBYTE_COMMAND(SentCommand.Data, 0x01))       // Blank Check

@@ -343,7 +359,12 @@ void EVENT_USB_UnhandledControlPacket(void)
 						if (Endpoint_BytesInEndpoint() == FIXED_CONTROL_ENDPOINT_SIZE)

 						{

 							Endpoint_ClearIN();

-							while (!(Endpoint_IsINReady()));

+

+							while (!(Endpoint_IsINReady()))

+							{				

+								if (USB_DeviceState == DEVICE_STATE_Unattached)

+								  return;

+							}

 						}

 

 						/* Read the flash word and send it via USB to the host */

@@ -368,7 +389,12 @@ void EVENT_USB_UnhandledControlPacket(void)
 						if (Endpoint_BytesInEndpoint() == FIXED_CONTROL_ENDPOINT_SIZE)

 						{

 							Endpoint_ClearIN();

-							while (!(Endpoint_IsINReady()));

+							

+							while (!(Endpoint_IsINReady()))

+							{				

+								if (USB_DeviceState == DEVICE_STATE_Unattached)

+								  return;

+							}

 						}

 

 						/* Read the EEPROM byte and send it via USB to the host */

@@ -385,10 +411,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 

 			Endpoint_ClearIN();

 

-			/* Acknowledge status stage */

-			while (!(Endpoint_IsOUTReceived()));

-			Endpoint_ClearOUT();

-

+			Endpoint_ClearStatusStage();

 			break;

 		case DFU_GETSTATUS:

 			Endpoint_ClearSETUP();

@@ -408,10 +431,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 

 			Endpoint_ClearIN();

 			

-			/* Acknowledge status stage */

-			while (!(Endpoint_IsOUTReceived()));

-			Endpoint_ClearOUT();

-	

+			Endpoint_ClearStatusStage();

 			break;		

 		case DFU_CLRSTATUS:

 			Endpoint_ClearSETUP();

@@ -419,10 +439,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 			/* Reset the status value variable to the default OK status */

 			DFU_Status = OK;

 

-			/* Acknowledge status stage */

-			while (!(Endpoint_IsINReady()));

-			Endpoint_ClearIN();

-			

+			Endpoint_ClearStatusStage();

 			break;

 		case DFU_GETSTATE:

 			Endpoint_ClearSETUP();

@@ -432,21 +449,15 @@ void EVENT_USB_UnhandledControlPacket(void)
 		

 			Endpoint_ClearIN();

 			

-			/* Acknowledge status stage */

-			while (!(Endpoint_IsOUTReceived()));

-			Endpoint_ClearOUT();

-

+			Endpoint_ClearStatusStage();

 			break;

 		case DFU_ABORT:

 			Endpoint_ClearSETUP();

 			

 			/* Reset the current state variable to the default idle state */

 			DFU_State = dfuIDLE;

-			

-			/* Acknowledge status stage */

-			while (!(Endpoint_IsINReady()));

-			Endpoint_ClearIN();

 

+			Endpoint_ClearStatusStage();

 			break;

 	}

 }

@@ -465,7 +476,11 @@ static void DiscardFillerBytes(uint8_t NumberOfBytes)
 			Endpoint_ClearOUT();

 

 			/* Wait until next data packet received */

-			while (!(Endpoint_IsOUTReceived()));

+			while (!(Endpoint_IsOUTReceived()))

+			{				

+				if (USB_DeviceState == DEVICE_STATE_Unattached)

+				  return;

+			}

 		}

 		else

 		{

diff --git a/Bootloaders/TeensyHID/TeensyHID.c b/Bootloaders/TeensyHID/TeensyHID.c
index 12d5c0de8..eed709783 100644
--- a/Bootloaders/TeensyHID/TeensyHID.c
+++ b/Bootloaders/TeensyHID/TeensyHID.c
@@ -119,7 +119,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 				

 				/* Wait until the command (report) has been sent by the host */

 				while (!(Endpoint_IsOUTReceived()));

-

+			

 				/* Read in the write destination address */

 				uint16_t PageAddress = Endpoint_Read_Word_LE();

 				

@@ -158,9 +158,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 

 				Endpoint_ClearOUT();

 

-				/* Acknowledge status stage */

-				while (!(Endpoint_IsINReady()));

-				Endpoint_ClearIN();

+				Endpoint_ClearStatusStage();

 			}

 			

 			break;