usb: dwc3: gadget: Report isoc transfer frame number
PATCH v3 2/2 usb: dwc3: gadget: Report isoc transfer frame number
Hi,
Quoted 23 lines · Thinh Nguyen
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drivers/usb/dwc3/gadget.c +0
-0@@ -2254,6 +2254,19 @@ static int dwc3_gadget_ep_reclaim_completed_trb(struct dwc3_ep *dep,if (chain && (trb->ctrl &DWC3_TRB_CTRL_HWO )) trb->ctrl &= ~DWC3_TRB_CTRL_HWO ;Quoted 14 lines
drivers/usb/dwc3/gadget.c static int dwc3_gadget_ep_reclaim_completed_trb(struct dwc3_ep *dep, · line 2268
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drivers/usb/dwc3/gadget.c +12
-0+/* +* For isochronous transfers, the first TRB in a service interval must +* have the Isoc-First type. Track and report its interval frame number. +*/ +if (usb_endpoint_xfer_isoc (dep->endpoint.desc) && + (trb->ctrl &DWC3_TRBCTL_ISOCHRONOUS_FIRST )) { +unsigned int frame_number; + + frame_number =DWC3_TRB_CTRL_GET_SID_SOFN (trb->ctrl); + frame_number &= ~(dep->interval -1 ); + req->request.frame_number = frame_number; + }could you refresh my memory on how this is going to be used?
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Sure. This informs the upper layer driver what interval the isoc request went out. The users can use this information for applications that require synchronization with the host.
Thanks. Do you have an example of a gadget that would use it? Perhaps g_webcam can rely on this to improve its scheduling? I have this in my testing/next already, just looking for an actual user :-)