On Wed, Sep 16, 2015 at 09:17:20AM -0500, Felipe Balbi wrote: > Hi Paul, good to get a mail from you :-) > > On Tue, Sep 15, 2015 at 04:31:03PM -0700, pauldzim . wrote: > > It's dangerous to use Update Transfer when the DWC3_TRB_CTRL_LST bit > > might be set in one of the TRBs. The reason is, there is a window > > between checking that the transfer has not completed yet and issuing > > the Update Transfer command. If the hardware happens to complete the > > transfer and see the DWC3_TRB_CTRL_LST bit set within that window, > > then the Update Transfer command will not work, and a Start Transfer > > command will be required instead. > > oh that's sad. It gave me such great improvements with MSC :-( Well, one > way would be to never use the LST bit, then I could even disable > XFER_COMPLETE event altogether. That would be a much more involved > rework though, much more likely to cause all sorts of regressions :-( oh great. A big chunk of the improvement was just about not waiting for XFER_NOT_READY. I'll send a new series shortly. -- balbi
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