From 08a36b543803b7fe39b66ca0529bea34a88dc77f Mon Sep 17 00:00:00 2001 From: Felipe Balbi Date: Thu, 11 Aug 2016 14:27:52 +0300 Subject: [PATCH] usb: dwc3: gadget: simplify __dwc3_gadget_ep_queue() Many of the comments in that function are really outdated and don't match what the driver is doing. Moreover, recent patches combined programming model for all non-control endpoints, this gives us an opportunity to get rid of our special cases in __dwc3_gadget_ep_queue(). Signed-off-by: Felipe Balbi --- drivers/usb/dwc3/gadget.c | 83 ++++------------------------------------------- 1 file changed, 7 insertions(+), 76 deletions(-) diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index a310266..3cf4c90 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -1063,18 +1063,6 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req) trace_dwc3_ep_queue(req); - /* - * We only add to our list of requests now and - * start consuming the list once we get XferNotReady - * IRQ. - * - * That way, we avoid doing anything that we don't need - * to do now and defer it until the point we receive a - * particular token from the Host side. - * - * This will also avoid Host cancelling URBs due to too - * many NAKs. - */ ret = usb_gadget_map_request(&dwc->gadget, &req->request, dep->direction); if (ret) @@ -1082,73 +1070,16 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req) list_add_tail(&req->list, &dep->pending_list); - /* - * If there are no pending requests and the endpoint isn't already - * busy, we will just start the request straight away. - * - * This will save one IRQ (XFER_NOT_READY) and possibly make it a - * little bit faster. - */ - if (!usb_endpoint_xfer_isoc(dep->endpoint.desc)) { - ret = __dwc3_gadget_kick_transfer(dep, 0); - goto out; - } - - /* - * There are a few special cases: - * - * 1. XferNotReady with empty list of requests. We need to kick the - * transfer here in that situation, otherwise we will be NAKing - * forever. If we get XferNotReady before gadget driver has a - * chance to queue a request, we will ACK the IRQ but won't be - * able to receive the data until the next request is queued. - * The following code is handling exactly that. - * - */ - if (dep->flags & DWC3_EP_PENDING_REQUEST) { - /* - * If xfernotready is already elapsed and it is a case - * of isoc transfer, then issue END TRANSFER, so that - * you can receive xfernotready again and can have - * notion of current microframe. - */ - if (usb_endpoint_xfer_isoc(dep->endpoint.desc)) { - if (list_empty(&dep->started_list)) { - dwc3_stop_active_transfer(dwc, dep->number, true); - dep->flags = DWC3_EP_ENABLED; - } - return 0; - } - - ret = __dwc3_gadget_kick_transfer(dep, 0); - if (!ret) - dep->flags &= ~DWC3_EP_PENDING_REQUEST; - - goto out; - } - - /* - * 2. XferInProgress on Isoc EP with an active transfer. We need to - * kick the transfer here after queuing a request, otherwise the - * core may not see the modified TRB(s). - */ if (usb_endpoint_xfer_isoc(dep->endpoint.desc) && - (dep->flags & DWC3_EP_BUSY) && - !(dep->flags & DWC3_EP_MISSED_ISOC)) { - WARN_ON_ONCE(!dep->resource_index); - ret = __dwc3_gadget_kick_transfer(dep, dep->resource_index); - goto out; + dep->flags & DWC3_EP_PENDING_REQUEST) { + if (list_empty(&dep->started_list)) { + dwc3_stop_active_transfer(dwc, dep->number, true); + dep->flags = DWC3_EP_ENABLED; + } + return 0; } - /* - * 4. Stream Capable Bulk Endpoints. We need to start the transfer - * right away, otherwise host will not know we have streams to be - * handled. - */ - if (dep->stream_capable) - ret = __dwc3_gadget_kick_transfer(dep, 0); - -out: + ret = __dwc3_gadget_kick_transfer(dep, 0); if (ret && ret != -EBUSY) dwc3_trace(trace_dwc3_gadget, "%s: failed to kick transfers", -- 2.7.4