usb: dwc3: gadget: Handle XferComplete for streams

In DWC3, to prepare TRBs for streams, all the TRBs of a transfer will
use the same stream ID. To start a new stream, the driver needs to wait
for the current transfer to complete or ended (by END_TRANFER command).
As a result, inform the controller of the last TRB of a transfer so that
it knows when a transfer completes and start a new transfer of a new
stream.

Even though the transfer completion handling can be applied for other
non-isoc endpoints, only do it for streams due to its requirement.
It's better to keep the controller's TRB cache full than waiting for
transfer completion and starting a new transfer.

Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 81aa7de4cb1791fc8bdb2a59d5ca29bed86f1078..052f6dc52a51e3dd97f61ead79c80399431bbc50 100644 (file)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -919,7 +919,8 @@ static u32 dwc3_calc_trbs_left(struct dwc3_ep *dep)
 
 static void __dwc3_prepare_one_trb(struct dwc3_ep *dep, struct dwc3_trb *trb,
                dma_addr_t dma, unsigned length, unsigned chain, unsigned node,
-               unsigned stream_id, unsigned short_not_ok, unsigned no_interrupt)
+               unsigned stream_id, unsigned short_not_ok,
+               unsigned no_interrupt, unsigned is_last)
 {
        struct dwc3             *dwc = dep->dwc;
        struct usb_gadget       *gadget = &dwc->gadget;
@@ -1012,6 +1013,8 @@ static void __dwc3_prepare_one_trb(struct dwc3_ep *dep, struct dwc3_trb *trb,
 
        if (chain)
                trb->ctrl |= DWC3_TRB_CTRL_CHN;
+       else if (dep->stream_capable && is_last)
+               trb->ctrl |= DWC3_TRB_CTRL_LST;
 
        if (usb_endpoint_xfer_bulk(dep->endpoint.desc) && dep->stream_capable)
                trb->ctrl |= DWC3_TRB_CTRL_SID_SOFN(stream_id);
@@ -1039,6 +1042,7 @@ static void dwc3_prepare_one_trb(struct dwc3_ep *dep,
        unsigned                stream_id = req->request.stream_id;
        unsigned                short_not_ok = req->request.short_not_ok;
        unsigned                no_interrupt = req->request.no_interrupt;
+       unsigned                is_last = req->request.is_last;
 
        if (req->request.num_sgs > 0) {
                length = sg_dma_len(req->start_sg);
@@ -1059,7 +1063,7 @@ static void dwc3_prepare_one_trb(struct dwc3_ep *dep,
        req->num_trbs++;
 
        __dwc3_prepare_one_trb(dep, trb, dma, length, chain, node,
-                       stream_id, short_not_ok, no_interrupt);
+                       stream_id, short_not_ok, no_interrupt, is_last);
 }
 
 static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
@@ -1104,7 +1108,8 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
                                        maxp - rem, false, 1,
                                        req->request.stream_id,
                                        req->request.short_not_ok,
-                                       req->request.no_interrupt);
+                                       req->request.no_interrupt,
+                                       req->request.is_last);
                } else {
                        dwc3_prepare_one_trb(dep, req, chain, i);
                }
@@ -1148,7 +1153,8 @@ static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep,
                __dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr, maxp - rem,
                                false, 1, req->request.stream_id,
                                req->request.short_not_ok,
-                               req->request.no_interrupt);
+                               req->request.no_interrupt,
+                               req->request.is_last);
        } else if (req->request.zero && req->request.length &&
                   (IS_ALIGNED(req->request.length, maxp))) {
                struct dwc3     *dwc = dep->dwc;
@@ -1165,7 +1171,8 @@ static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep,
                __dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr, 0,
                                false, 1, req->request.stream_id,
                                req->request.short_not_ok,
-                               req->request.no_interrupt);
+                               req->request.no_interrupt,
+                               req->request.is_last);
        } else {
                dwc3_prepare_one_trb(dep, req, false, 0);
        }
@@ -2718,6 +2725,19 @@ static void dwc3_gadget_endpoint_transfer_in_progress(struct dwc3_ep *dep,
        dwc3_gadget_endpoint_trbs_complete(dep, event, status);
 }
 
+static void dwc3_gadget_endpoint_transfer_complete(struct dwc3_ep *dep,
+               const struct dwc3_event_depevt *event)
+{
+       int status = 0;
+
+       dep->flags &= ~DWC3_EP_TRANSFER_STARTED;
+
+       if (event->status & DEPEVT_STATUS_BUSERR)
+               status = -ECONNRESET;
+
+       dwc3_gadget_endpoint_trbs_complete(dep, event, status);
+}
+
 static void dwc3_gadget_endpoint_transfer_not_ready(struct dwc3_ep *dep,
                const struct dwc3_event_depevt *event)
 {
@@ -2781,8 +2801,10 @@ static void dwc3_endpoint_interrupt(struct dwc3 *dwc,
                        dep->flags &= ~DWC3_EP_DELAY_START;
                }
                break;
-       case DWC3_DEPEVT_STREAMEVT:
        case DWC3_DEPEVT_XFERCOMPLETE:
+               dwc3_gadget_endpoint_transfer_complete(dep, event);
+               break;
+       case DWC3_DEPEVT_STREAMEVT:
        case DWC3_DEPEVT_RXTXFIFOEVT:
                break;
        }