LPC2140 usb msc deferred out package processing

a fiendly hello to the keil arm7 forum members !!!

i need to move the msc data and control processing fron the isr
runtime into the main background loop.

i took the following steps :

1) file mscuser.c function MSC_GetCBW.c

deferred processing of the following commands

case SCSI_TEST_UNIT_READY: case SCSI_REQUEST_SENSE: case SCSI_INQUIRY: case SCSI_MODE_SENSE6: case SCSI_MODE_SENSE10: case SCSI_READ_FORMAT_CAPACITIES: case SCSI_READ_CAPACITY:

case SCSI_READ10:

by using a command variable which holds the current command and parse
them in a 2nd switch statement the main loop and calling the following
functions now from the main loop

MSC_TestUnitReady(); MSC_RequestSense(); MSC_Inquiry(); MSC_ModeSense6(); MSC_ModeSense10(); MSC_ReadFormatCapacity(); MSC_ReadCapacity();

MSC_MemoryRead();

this works fine since all of these commands are usb "in" commands and
not "out" commands

the MSC_MemoryRead() is also deferred processed in a similar way
in the function MSC_BulkIn

case MSC_BS_DATA_IN:

this all works fine so far, but here comes the real problem

2) i apply a similar defer technique in the main loop to the

MSC_MemoryWrite(); case in function MSC_BulkOut

i also move the line

BulkLen = USB_ReadEP(MSC_EP_OUT, BulkBuf);

from the isr into the main loop to avoid ack'ing the receipt of the usb out package until i process it in the main loop. (the ack / nack of the out package in slave mode in the last step is an assumption of
mine)

3) the implementation of step 2 does not succeed.

what am i doing wrong ???

how can i move the processing of usb out packages from the isr domain
into the main loop domain ???

any help and suggestions are highly appreciated

thanks, Klaus