Commit 7b9cc7a2 authored by Konrad Leszczynski's avatar Konrad Leszczynski Committed by Felipe Balbi
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usb: dwc3: gadget: give better command return code 



if Start Transfer command fails, let's try a little
harder to figure out why the command failed and give
slightly better return codes. This will be usefulf
or isochronous endpoints, at least, which could
decide to retry a given request.

Signed-off-by: default avatarKonrad Leszczynski <konrad.leszczynski@intel.com>
Signed-off-by: default avatarRafal Redzimski <rafal.f.redzimski@intel.com>
Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
parent 0878263b

drivers/usb/dwc3/core.h

+4 −0
Original line number Diff line number Diff line
@@ -970,6 +970,10 @@ struct dwc3_event_depevt { 
#define DEPEVT_STATUS_CONTROL_DATA	1

#define DEPEVT_STATUS_CONTROL_STATUS	2



/* In response to Start Transfer */

#define DEPEVT_TRANSFER_NO_RESOURCE	1

#define DEPEVT_TRANSFER_BUS_EXPIRY	2



	u32	parameters:16;

} __packed;

drivers/usb/dwc3/gadget.c

+30 −3
Original line number Diff line number Diff line
@@ -287,12 +287,39 @@ int dwc3_send_gadget_ep_cmd(struct dwc3 *dwc, unsigned ep, 
	do {

		reg = dwc3_readl(dwc->regs, DWC3_DEPCMD(ep));

		if (!(reg & DWC3_DEPCMD_CMDACT)) {

			int cmd_status = DWC3_DEPCMD_STATUS(reg);



			dwc3_trace(trace_dwc3_gadget,

					"Command Complete --> %d",

					DWC3_DEPCMD_STATUS(reg));

			if (DWC3_DEPCMD_STATUS(reg))

				break;

					cmd_status);



			switch (cmd_status) {

			case 0:

				ret = 0;

				break;

			case DEPEVT_TRANSFER_NO_RESOURCE:

				dwc3_trace(trace_dwc3_gadget, "%s: no resource available");

				ret = -EINVAL;

				break;

			case DEPEVT_TRANSFER_BUS_EXPIRY:

				/*

				 * SW issues START TRANSFER command to

				 * isochronous ep with future frame interval. If

				 * future interval time has already passed when

				 * core receives the command, it will respond

				 * with an error status of 'Bus Expiry'.

				 *

				 * Instead of always returning -EINVAL, let's

				 * give a hint to the gadget driver that this is

				 * the case by returning -EAGAIN.

				 */

				dwc3_trace(trace_dwc3_gadget, "%s: bus expiry");

				ret = -EAGAIN;

				break;

			default:

				dev_WARN(dwc->dev, "UNKNOWN cmd status\n");

			}



			break;

		}

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