On Thu, Dec 06, 2012 at 08:49:08AM +0000, Nikunj Sanghani wrote: > 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? That's a hardware question, not a kernel driver question, right? > 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? What does the xhci driver to today in this case in your testing? thanks, greg k-h -- 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
