Hi, Suppose one TD that has 5 TRBs and each has trb Length of 200 bytes except last Trb all have chain bit set to 1. Single TD contains 5 TRBs. -------------------------------------- | ------------------------- | | |trnlen =200 chain=1 | TRB=1 | | ------------------------- | | ------------------------- | | |trnlen =200 chain=1 | TRB=2 | | ------------------------- | | ------------------------- | | |trnlen =200 chain=1 | TRB=3 | | ------------------------- | | ------------------------- | | |trnlen =200 chain=1 | TRB=4 | | ------------------------- | | ------------------------- | | |trnlen =200 chain=0 | TRB=5 | | ------------------------- | -------------------------------------- Now in this case XHC should transfer individual TRBs to USB pipe or it should wait till the completion of TD and then transfer the chunk of data to USB pipe? Software will ring the doorbell after adding all TRB in TD or software can ring the doorbell after loading one TRB of TD and after that add TRBs simultaneously on Ring? Thanks, Nikunj -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html