Fixed Mass Storage Host Class driver and Low Level demo not clearing the error condition if an attached device returns a STALL to a GET MAX LUN request (thanks to Martin Luxen).

1 files changed, 9 insertions, 2 deletions

diff --git a/Demos/Host/LowLevel/MassStorageHost/Lib/MassStoreCommands.c b/Demos/Host/LowLevel/MassStorageHost/Lib/MassStoreCommands.c
index ff01dc0f2..edd142525 100644
--- a/Demos/Host/LowLevel/MassStorageHost/Lib/MassStoreCommands.c
+++ b/Demos/Host/LowLevel/MassStorageHost/Lib/MassStoreCommands.c
@@ -287,13 +287,17 @@ uint8_t MassStore_MassStorageReset(void)
 /** Issues a Mass Storage class specific request to determine the index of the highest numbered Logical

  *  Unit in the attached device.

  *

+ *  \note Some devices do not support this request, and will STALL it when issued. To get around this,

+ *        on unsupported devices the max LUN index will be reported as zero and no error will be returned

+ *        if the device STALLs the request.

+ *

  *  \param[out] MaxLUNIndex  Pointer to the location that the maximum LUN index value should be stored

  *

  *  \return A value from the USB_Host_SendControlErrorCodes_t enum, or MASS_STORE_SCSI_COMMAND_FAILED if the SCSI command fails

  */

 uint8_t MassStore_GetMaxLUN(uint8_t* const MaxLUNIndex)

 {

-	uint8_t ErrorCode;

+	uint8_t ErrorCode = HOST_SENDCONTROL_Successful;

 

 	USB_ControlRequest = (USB_Request_Header_t)

 		{

@@ -313,7 +317,10 @@ uint8_t MassStore_GetMaxLUN(uint8_t* const MaxLUNIndex)
 		Pipe_ClearStall();

 	

 		/* Some faulty Mass Storage devices don't implement the GET_MAX_LUN request, so assume a single LUN */

-		*MaxLUNIndex = 0;	

+		*MaxLUNIndex = 0;

+		

+		/* Clear the error, and pretend the request executed correctly if the device STALLed it */

+		ErrorCode = HOST_SENDCONTROL_Successful;

 	}

 	

 	return ErrorCode;