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usb: dwc3: gadget: return errors from __dwc3_gadget_start_isoc()

PATCH New Laurent Pinchart 1 participant 1 message Aug 20, 2018 USB

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Laurent Pinchart

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PATCH 1/4 usb: dwc3: gadget: return errors from __dwc3_gadget_start_isoc()

Hi Felipe,

Thank you for the patch.

Quoted 37 lines · On Monday, 20 August 2018 13:29:58 EEST Felipe Balbi wrote:

Sometimes, errors happen when kicking transfers from __dwc3_gadget_start_isoc(). In those cases, we need to pass along the error so gadget driver can make informed decisions.

Signed-off-by Felipe Balbi <[email protected]>
---
 drivers/usb/dwc3/gadget.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)
drivers/usb/dwc3/gadget.c +3 -3
index 69bf137aab37..f61a4250c883 100644
@@ -1255,17 +1255,17 @@ static int __dwc3_gadget_get_frame(struct dwc3 *dwc)
 return DWC3_DSTS_SOFFN(reg);
 }
 
-static void __dwc3_gadget_start_isoc(struct dwc3_ep *dep)
+static int __dwc3_gadget_start_isoc(struct dwc3_ep *dep)
 {
 	if (list_empty(&dep->pending_list)) {
 		dev_info(dep->dwc->dev, "%s: ran out of requests\n",
 				dep->name);
 		dep->flags |= DWC3_EP_PENDING_REQUEST;
-		return;
+		return -EAGAIN;
 	}
 
 	dep->frame_number = DWC3_ALIGN_FRAME(dep);
-	__dwc3_gadget_kick_transfer(dep);
+	return __dwc3_gadget_kick_transfer(dep);
 }
 
 static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request

*req) @@ -1306,8 +1306,7 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)

drivers/usb/dwc3/gadget.c

Quoted 5 lines
drivers/usb/dwc3/gadget.c +1 -2
 		if ((dep->flags & DWC3_EP_PENDING_REQUEST)) {
 			if (!(dep->flags & DWC3_EP_TRANSFER_STARTED)) {
-				__dwc3_gadget_start_isoc(dep);
-				return 0;
+				return __dwc3_gadget_start_isoc(dep);

Do I understandand correctly that the new -EAGAIN error returned above when an underrun has occurred will never be returned here, as we call __dwc3_gadget_start_isoc() after adding a request to the pending_list, covered by the same spinlock that is taken by the IRQ handler to remove requests from the list ? I don't think that's an issue, but I want to make sure nothing is overlooked.

drivers/usb/dwc3/gadget.c

Quoted 10 lines
drivers/usb/dwc3/gadget.c +0 -0
 			}
 		}
 	}

@@ -2427,7 +2426,7 @@ static void

dwc3_gadget_endpoint_transfer_not_ready(struct dwc3_ep *dep, const struct dwc3_event_depevt *event)
{

drivers/usb/dwc3/gadget.c +1 -1
 	dwc3_gadget_endpoint_frame_from_event(dep, event);
-	__dwc3_gadget_start_isoc(dep);
+	(void) __dwc3_gadget_start_isoc(dep);

No need for a cast here.

Quoted 3 lines

}

static void dwc3_endpoint_interrupt(struct dwc3 *dwc,