Commit d5370106 authored by Felipe Balbi's avatar Felipe Balbi
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usb: dwc3: gadget: check if dep->frame_number is still valid 



Gadget driver may take an unbounded amount of time to queue requests
after XferNotReady. This is important for isochronous endpoints which
need to be started for a specific (micro-)frame.

If we fail to start a transfer for isochronous endpoint, let's try
queueing to a future interval and see if that helps. We will stop trying
if we fail a start transfer for 5 intervals in the future.

Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
parent 3451f6af

drivers/usb/dwc3/core.h

+1 −0
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ 
#define DWC3_EP0_SETUP_SIZE	512

#define DWC3_ENDPOINTS_NUM	32

#define DWC3_XHCI_RESOURCES_NUM	2

#define DWC3_ISOC_MAX_RETRIES	5



#define DWC3_SCRATCHBUF_SIZE	4096	/* each buffer is assumed to be 4KiB */

#define DWC3_EVENT_BUFFERS_SIZE	4096

drivers/usb/dwc3/gadget.c

+12 −3
Original line number Diff line number Diff line
@@ -27,7 +27,7 @@ 
#include "gadget.h"

#include "io.h"



#define DWC3_ALIGN_FRAME(d)	(((d)->frame_number + (d)->interval) \

#define DWC3_ALIGN_FRAME(d, n)	(((d)->frame_number + ((d)->interval * (n))) \

					& ~((d)->interval - 1))



/**
@@ -1384,6 +1384,8 @@ static int dwc3_gadget_start_isoc_quirk(struct dwc3_ep *dep) 
static int __dwc3_gadget_start_isoc(struct dwc3_ep *dep)

{

	struct dwc3 *dwc = dep->dwc;

	int ret;

	int i;



	if (list_empty(&dep->pending_list)) {

		dep->flags |= DWC3_EP_PENDING_REQUEST;
@@ -1400,8 +1402,15 @@ static int __dwc3_gadget_start_isoc(struct dwc3_ep *dep) 
			return dwc3_gadget_start_isoc_quirk(dep);

	}



	dep->frame_number = DWC3_ALIGN_FRAME(dep);

	return __dwc3_gadget_kick_transfer(dep);

	for (i = 0; i < DWC3_ISOC_MAX_RETRIES; i++) {

		dep->frame_number = DWC3_ALIGN_FRAME(dep, i + 1);



		ret = __dwc3_gadget_kick_transfer(dep);

		if (ret != -EAGAIN)

			break;

	}



	return ret;

}



static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)