On Thu, Nov 16, 2023, Manan Aurora wrote: > On Sat, Nov 11, 2023 at 4:39 AM Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx> wrote: > > > > On Thu, Nov 02, 2023, Manan Aurora wrote: > > > Support configuration and use of bulk endpoints in the so-called EBC > > > mode described in the DBC_usb31 databook (appendix E) > > > > > > Added a bit fifo_mode to usb_ep to indicate to the UDC driver that a > > > specific endpoint is to operate in the EBC (or equivalent) mode when > > > enabled > > > > This should be unique to dwc3, and it's only for bulk. I don't think > > usb_ep or the user of usb_ep should know this. > > In our use case we have a function driver that configures an allocated bulk > endpoint to operate as an EBC EP. So the function driver already depends on the > feature. This should be abstracted from the function driver. The function driver should not need to know about this feature. > > dwc3_ep seems like the correct place to put this field but a function > driver that allocates > EPs and configures them for this use case would need to include dwc3 headers. > If other vendors offer an equivalent feature this dependency would > become an issue. > > Exporting a symbol from dwc3 is an easy option but dwc3 doesn't > currently export symbols > hence I tried to avoid that > > > Also since DWC3_DEPCFG_EBC_HWO_NOWB must be set, the controller does not > > write back to the TRB. Did you handle how the driver would update the > > usb request on completion? (e.g. how much was transferred). > > In our use case, we intend to have a link TRB and issue a startXfer > command. Completion > handling and continuing the transfer will be offloaded to dedicated > FIFO hardware. > But we can definitely rework this to disable no-writeback mode by > default and allow this to > be separately enabled > Ok. Thanks, Thinh
